Maatalous- metsätieteellinen tiedekunta


Recent Submissions

  • Lamminen, Marjukka (Helsingin yliopisto, 2019)
    The objective of the research described in this thesis was to evaluate the potential and sustainability of protein feed use of different non-defatted microalgae species in the nutrition of lactating dairy cows. Four physiological experiments (Publications I-III) were conducted with dairy cows to compare dry matter (DM) intake, milk production, energy metabolism, nitrogen (N) utilisation and amino acid (AA) metabolism using diets containing microalgae (Spirulina platensis, Chlorella vulgaris and Nannochloropsis gaditana) and conventional protein feeds (rapeseed meal, soya bean meal and faba beans). The microalgae diets constituted of S. platensis (Exp. 2, 3 and 4; I-III), C. vulgaris (Exp. 3; II), mixture of S. platensis and C. vulgaris (Exp. 1; I), and mixture of C. vulgaris and N. gaditana (Exp. 3; II). These microalgae substituted protein in rapeseed meal partially (Exp. 1, 2 and 4; I, III) or completely (Exp. 1 and 2; I), soybean meal completely (Exp. 3; II), and faba beans partially (Exp. 4; III). In addition, the effect of protein supplementation with rapeseed meal and microalgae in comparison to unsupplemented diet (Exp. 2; I) was studied. The crude protein (CP; Kjeldahl-N × 6.25) concentration of microalgae was on average 690 g/kg DM for S. platensis, 597 g/kg DM for C. vulgaris and 385 g/kg DM for N. gaditana. These microalgae were relatively low in crude fat, with highest concentration of 192 g/kg DM measured for N. gaditana. Compared to conventional protein feeds, all microalgae were lower in histidine, but higher in methionine. The DM intake (DMI) of microalgae containing feeds was lower than that of conventional protein feeds in three out of four experiments. When forage and concentrates were fed separately, cows compensated the decreased intake of microalgae containing concentrates by increasing silage intake (Exp. 2 and 3; I-II). Thus, total DMI remained unchanged (Exp. 2 and 3; I, II). This decreased the proportion of concentrate in the diet as much as 11.4 %-units. When all feed components were offered as total mixed ration (TMR), total DMI was decreased (on average 0.65 kg/d) as cows no longer were able to avoid microalgae (Exp. 4; III). The poor palatability of microalgae was not related to amount of microalgae in the diet, dietary crude fat concentration or stage of lactation. Milk yield was unaffected by microalgae inclusion in the diet in three out of four experiments. The partial substitution of rapeseed meal or faba beans with S. platensis decreased milk yield on rapeseed, but increased on faba bean supplemented diets (Exp. 4; III). The same was observed as a tendency for protein yield. Also in Experiment 2 (I), S. platensis tended to result in lower milk protein yield than rapeseed meal. Microalgae resulted in milk, energy corrected milk (ECM) and protein yields similar to soya bean meal (Exp. 3; II). S. platensis inclusion in the diet increased milk fat concentration on soya (Exp. 3; II) and rapeseed meal (Exp. 4; III) supplemented diets, which might have been caused by more acetate intensive ruminal fermentation, increased body mobilisation or higher methionine intake. Protein supplementation increased N excretion in urine and faeces, and decreased the conversion efficiency of dietary N into milk protein (milk N:N intake; NUE) (Exp. 2; I). The responses of microalgae inclusion in the diet depended on the source of protein in the basal diet. In Exp. 2 (I), the substitution of rapeseed meal with S. platensis decreased NUE and human-edible protein efficiency. The same was observed in Exp. 4 (III) on rapeseed meal supplemented diets, whereas on faba bean supplemented diets NUE was increased and human-edible protein efficiency was unaffected by S. platensis inclusion in the diet. In addition, the partial substitution of both rapeseed meal and faba beans resulted in increased urinary and total excretion of N (Exp. 4; III). The complete substitution of soya bean meal with different microalgae did not affect NUE, but decreased urinary N excretion and tended to increase human-edible protein efficiency. The substitution of all conventional protein feeds with microalgae decreased the intake of histidine and increased that of methionine. In three out of four experiments, these changes did not convert to major changes in arterial concentrations of these AA and their metabolites. The changes observed with S. platensis inclusion in the diet were tendency for lower arterial histidine concentration in Exp. 2 (II), decreased mammary uptake of histidine in Exp. 2(II) and methionine in Exp. 4 (III). In conclusion, the results demonstrated no biological or physiological constraints for protein feed use of different microalgae. Moreover, microalgae seemed to be suitable substitute for soya bean meal and faba beans in dairy cow nutrition. However, microalgae are slightly inferior to rapeseed meal as indicated by results of milk production and N utilisation. The greatest challenge limiting the feed use of microalgae for lactating dairy cows is their poorer palatability relative to conventional feeds.
  • Matilainen, Anne (Helsingin yliopisto, 2019)
    This dissertation focuses on analysing the feelings of ownership that the owners and other users of forests have developed towards privately-owned forest resources. These resources play a major part in providing forest-based benefits to society, as a large proportion of the forests in Europe and the US are privately owned by so called non-industrial private forest owners (NIPF). Therefore, the decisions the NIPF owners make regarding their forest resources have a direct impact on the availability of forest-based ecosystem services. Due to the importance of the private forest resources at global, national and local levels, it is not surprising that a vast number of regulations and land use practices have been developed, that set the regulatory framework for the use of forests. Thus also, users other than the owners feel that they have the right to speak about the use of forests. Due to these demands and the expectations from the wider society, the forest owners do not have sole control over their forest areas. In the best case, nevertheless, the objectives of both private forest owners and various society’s objectives for the forests could be met at the same time. This necessitates a profound understanding of the forest owners’ own objectives, values and motivations regarding their forests. This dissertation contributes to the research on forest ownership by introducing a novel concept, psychological ownership, as a potential approach to understanding the possessive feelings towards privately-owned forests, and via that, a better understanding of the role of these feelings in the behaviour of forest owners and other forest users (in this case nature-based tourism entrepreneurs). Psychological ownership is based on the idea that ownership should not be understood only as a legal construct, but also to include certain psychological elements i.e. to the feeling “it is mine”. Originally, psychological ownership was introduced in the field of organizational research, but it has since been applied increasingly in other sectors. In this study, it is used as the theoretical background to understand the ownership feelings about private forest resources. Psychological ownership can also bring a new approach to study the co-operation relationships related to the use of forests by multiple stakeholders, for example, when introducing new potential uses of forest resources (in this case nature-based entrepreneurship). The study is qualitative in nature and the data consist of thematic interviews with private forest owners and nature tourism entrepreneurs. The results summarise the findings from three published journal articles. They show that both the legal owners and the nature-based entrepreneurs utilizing private forest areas seem to have developed psychological ownership feelings towards these forests. However, these feelings are not necessarily dependent on the legal ownership of the resource. Furthermore, the psychological ownership experienced seems to influence the behaviour of the persons expressing these feelings, for example, related to the private forest owners’ forest management decisions. The results also illustrate that recognizing psychological ownership can help in understanding successful co-operation relationships and potential conflict situations relating to the multiple use of forest resources. In practice, it could help to foresee or even manage the potential conflicts.
  • Alho, Eeva (Helsingin yliopisto, 2019)
    In the wake of the modernization of agriculture and agricultural markets, the role of the farmer has increasingly moved towards that of an owner and investor in agricultural producer cooperatives. Competitive pressures, internationalization, and the growth of cooperatives call for an examination of new avenues for acquiring investment capital, as the traditional cooperative structure may fail to provide sufficient incentives to urge members to contribute to the long-term success of the cooperative. Despite an emerging multitude of new cooperative structures, the investment preferences of cooperative members are not sufficiently understood. Moreover, the preferences of potential non-member investors beyond cooperative boundaries remain practically unexplored. This dissertation consists of four essays around the theme of investment behavior in agricultural producer cooperatives. The analyses are based on questionnaire data from Finnish dairy farmers and financial market professionals. The farmer survey examined member preferences concerning the use of cooperative surplus for investments as well as their views on new cooperative investment instruments. The investor survey studied the willingness of non-members to invest in agricultural production and the behavioral motivations affecting their investment decisions. The study methods applied here are novel to the context of investment in cooperatives. The results offer insights into new possibilities to develop capital sourcing strategies for use by growth-seeking agricultural producer cooperatives. An understanding of investor preferences will facilitate the design of new financing mechanisms for cooperatives.
  • Uimonen, Sirpa (Helsingin yliopisto, 2019)
    My research is about the sense of home comprehended as the entirety of meanings. My approach was to look at the sense of home from the phenomenological stance and from the experiences of the consumer. Utilizing the theory of practice I examined the elements of the sense of home and their significance by means of a theme interview. The theme interviews were organized in Finland and in the Portuguese Algarve. The analysis of the interview transcripts was done as a text analysis using Atlas.Ti7. The analysis is primarily based on themes-analysis. Resulting from the analysis, there emerged several different entireties of the sense of home. Each sense of home entirety is framed by a concrete observed space, an abstract imagined space, and a living space. The practical space means easy everyday life and the functionality of home-based practices. The space is relatively clean and tidy. The homely lair manifested itself as snuggling down and emphasizing all kinds of comfort. The homely lair is a private space. The objects at home remind the occupant of his or her personal history and the loved ones. For many, a homely lair was made to the second home. In the space, the loved ones — even the late ones — are present. The feeling of a homely lair was also brought into the second home in the Algarve. Specifically, the second home in the Algarve is clearly a place for the peace of mind, which is best described by the desire for freedom, freedom from duties, external timetables and pressures. The sense of home can be merely an inner state of mind, which is not necessarily tied to a particular geographical place. The sense of home can be present here and now or in an imagination. The stimulating ambience is a comprehensive feeling conveyed by multiple senses. Experiences rise in the home space, of the home space, of the environment and of the imagination, and of the virtual world that complements the visible reality. The creator of the ambience actualizes herself and wants to involve other people as part of the ambience both as evaluators and as audience. One significant result relates to material. Home in Finland is furnished with objects and things, intangible objects and virtual material. In the second home abroad, however, the mobile consumers want to efface the solid personal meaning of things. Housing, furnishing and moving around are preferentially organized through services. The study complements and updates the definition of comfort. Earlier layers of domestic comfort include privacy, leisure, ease, comfortable furnishings, heat, light, ventilation, household appliances, efficiency, running water, indoor toilet and bathroom. New layers of comfort are abstract requirements of time management, to synchronize one's everyday life with the rhythms of the environment, and the desire to take control of one's own life.
  • Simola, Antti (Helsingin yliopisto, 2019)
    Global food production will face several challenges in the future. Population continues growing, and expansion of agricultural area is becoming more difficult. A common view is that yields need to double by 2050. The goal is not without challenges: expansion will contribute to deforestation, habitat loss and carbon emissions, while productivity increases could contribute to nutrient run-offs, increased greenhouse gas emissions and land degradation. The scientific community recommends sustainable intensification as the best way to reckon with the challenges. However, adequate policy measures need to be in place for that end to be achievable. This dissertation provides new findings to support better informed policy decisions. The essays in this dissertation examine the interrelationship between agricultural policies and land use from various angles. The approach is empiric, and the dissertation aims to further define how policy measures affect farmers' land use decisions. The empirical analysis aims to improve predictions on the effects of policy measures. Special focus is on how policies steer land use in the direction of sustainable intensification. Essay I examines the modeling of intensive margin adjustment of agricultural land use in computable general equilibrium (CGE) models, which are widely used to analyze land use change. The analysis is based on empirical estimation of agricultural production functions with Finnish farm-level data. The results indicate that the CRESH functional form should be favored over its alternatives. The subsequent CGE model simulations showed that both the elasticity estimates and the choice of functional form affect the model results significantly. Consequently, the widely-applied CES functional forms likely underestimate the elasticity of the intensive margin adjustment, and thus the adaptation possibilities in the agricultural sector as a whole. Essay II examines how policies and markets interact in the structural change of agricultural sector. The model applied is based on Fisher's principle, which explains variables' evolution as regards underlying fitness factors. This essay examines both land input and output markets separately with respect to both market and subsidy income. The empirical analysis employs quantile regression techniques that can shed light on the effects of the whole range of distribution values in addition to the mean effects. The results show that decoupled subsidies have increased the market-orientation of the sector concurrently with increasingly inefficient allocation of land. However, the latter effect was found to dominate, which indicates a negative net effect. Additionally, the distinction between coupled and decoupled subsidies matters very little in comparison to the effects that the subsidies have when paid in one form or another. Subsidies and market incomes attenuate each other, and thus they direct structural change in different directions. Decoupling has increased land market rigidities and thus inefficient allocation of land. Essay III examines how farmers adjust their land use to coupled, crop-specific subsidy payments. It exploits an idiosyncratic policy change in the Agenda 2000 reform as a quasi-experimental setting. The causality between the subsidy payments and production decisions could be reliably established with the standard differences-in-differences model. A range of empirical strategies suitable for the task are explored, while the results of OLS fixed effects and fractional response models are reported as they were considered the most reliable. The results vary between the models, which nevertheless does not affect the main conclusions. The results show that the reform affected farmers' land use decisions as predicted by economic theory: a crop's area increases (decreases) if its subsidy payment increases (decreases). Furthermore, allocation decisions are very elastic to coupled subsidies, especially for feed crops.
  • Makkonen, Marika (Helsingin yliopisto, 2019)
    Sahateollisuuden liiketoimintastrategiat perustuvat perinteiseen (tuotelähtöiseen) liiketoimintalogiikkaan. Perinteiset kilpailukyvun lähteet, kuten alhaisemmat hinnat tai tuotannon tehokkuus, eivät ole enää riittäviä turvaamaan sahateollisuuden kannattavuutta. Siirtyminen valmistusyrityksestä palveluliiketoimintaan sisältää merkittävää potentiaalia asiakkaan kokeman arvon kasvattamiseen ja siten sahateollisuuden kilpailukyvyn parantamiseen. Palveluliiketoiminnan perusajatuksena on arvonluonti yhteistyössä palvelun tuottajan, asiakkaan ja muiden osapuolten kanssa. Näin ollen asiakas on liiketoiminnan keskiössä, haastaen perinteistä tuotelähtöistä ajattelutapaa. Työn tavoitteena on selvittää sahateollisuuden liiketoimintamallin muutosta kohti asiakasläjtöisyyttä ja palveluliiketoimintaa. Koska arvoketjun toimijat ovat kytköksissä toisiinsa, tutkimuksessa tarkastellaan koko puutuoteteollisuutta. Muutosta kuvataan palvelulogiikan avulla (service logic), joka korostaa yrityksen ja asiakkaan välistä vuorovaikutusta. Työn uutuusarvo on asiakaslähtöisyyden ja palvelulogiikan soveltaminen sahateollisuuden kontekstissa. Lisäksi siinä tarkastellaan innovaation ja digitalisaation merkitystä alan kilpailukyvyn lähteenä. Tulokset perustuvat sekä tapaus- että haastattelututkimuksiin (n = 36). Tulosten perusteella saha- ja puutuoteteollisuudella on paljon hyödyntämätöntä potentiaalia kilpailukykyvyn kasvattamiseksi, jonka se voi savuttaa siirtymällä kohti asiakaslähtöisyyttä ja palveluiliikeotimintaa. Siirtyminen vaatii merkittäviä strategisia muutoksia, kyseenalaistaen nykyiset toimintatavta ja periaatteet. Muutos alkaa ymmärryksellä siitä, mitä asiakaslähtöisyys merkitsee. Tarvitaan lisää ymmärrystä asiakkaiden tarpeista ja prosesseista, joiden perusteella yritykset voivat arvioida ja kehittää omaa tarjoomaansa. Keskeistä palveluliiketoiminnan onnistumisessa on asenteiden muutos kohti asiakaslähtöisyyttä – ei pelkästään omassa organisaatiossa, vaan läpi arvoketjujen.
  • Tolonen, Sanna (Helsingin yliopisto, 2019)
    Previous findings suggest that bone mineral density and bone loss are highly genetically determined but the further details of bone genetics remain partly unknown. In thesis, it was studied for the first time whether the single nucleotide polymorphisms of lactase and apolipoprotein E (APOE) genes are associated with the peripheral quantitative computed tomography (pQCT) bone traits of radius and tibia. In addition to the gene polymorphisms, the associations of physical activity in childhood and adulthood with various bone traits as outcomes were examined. This is also a current topic since despite the fact that bone-loading physical activities are essential in building healthy bones; it seems that modern communities do not encourage most of us to move and exercise enough. Study subjects of the present thesis are part of the Cardiovascular Risk in Young Finns Study which was initiated in 1980 with 3596 persons aged 3, 6, 9, 12, 15 and 18. The findings presented are additionally based on the follow-ups conducted in 1986, 2001 and 2007. The pQCT and quantitative ultrasound bone measurements and fracture data were collected in 2008 when the participants were 31-46 years old. Lactase C/T-13910 genotyping (rs4988235) was performed using a 5’ nuclease assay and the APOE genotypes (rs429358 and rs7412) and the APOE promoter polymorphisms -219 and +113 (rs405509 and rs440446) using TaqMan SNP genotyping assays. Dietary intakes were collected through 48-hour dietary recall interviews and later in 2007 with a 131-item food frequency questionnaire. Physical activity in childhood was assessed using a questionnaire including items on leisure-time physical activity, organised exercise, participation in competitions, and intensity level. In adulthood, pedometer-determined steps were used to quantify the amount of physical activity undertaken in 2007. In Study I, small differences in trabecular densities at the distal sites of radius and tibia were found in men between the lactase genotypes. Men with the T/T genotype had ~3% higher values than the carriers of T/C and C/C genotypes. They also had higher calcium intake than men carrying the C allele. In Study II, the carriers of the APOE ԑ4 allele had higher total-cholesterol and LDL-cholesterol serum concentrations than the non-carriers. In addition, the ԑ4 allele was associated with some lower cortical density but greater bone mineral content (BMC) at the tibial diaphysis. Women with the APOE promoter -219T/T allele had on average 7-8% lower cortical and compressive strengths at the distal sites of radius and tibia than the female G/G carriers. At the tibial shaft, the mean values of cortical strength were 2-2.5% lower in subjects with the -219T/T allele compared to the G/G carriers. Men with the -219T/T allele also had 1-2% lower cortical density and cortical strength at the radial shaft but 4-5% greater total areas at the radius than men with the G/G allele. In addition, women with the -219T/T allele whose longitudinal saturated fat intake was the highest (≥35.5 g/day) had the lowest total area and torsional strength at the radial shaft. Almost identical results were found in women and men with the +113G/C genotypes (G/G, G/C and C/C) as reported for the -219G/T genotypes (G/G, G/T and T/T). In Study III, there were no statistically significant differences in the risk of low-energy fractures between the different physical activity groups of 3-18-year-old children and adolescents. In addition, no differences were found in adult tibial traits between the physical activity groups of 3-6-year-olds. In females, the highest level of physical activity at the age of 9-18 years was significantly associated with a lower likelihood of below median values of compressive strength at the distal tibia, and total and cortical areas, and BMC and strength indices at the tibial shaft compared to the lowest activity level in adolescence (ORs 0.33-0.53). Similarly in males, total area at the distal site and cortical area and strength at the tibial shaft were less likely to be below the median values in the highest physical activity group compared to the lowest activity group of adolescents (ORs 0.48-0.53). In Study IV, women within the highest tertile of daily steps had 3.8% and 0.5% greater broadband ultrasound attenuation and speed of sound at the calcaneus compared to women in the lowest tertile. In tibia, women in the highest tertile (> 8765 daily steps) had on average 1-5.4% greater bone cross-sectional area, BMC, trabecular density and compressive strength at the distal site and 1.6-2.7% greater total and cortical bone areas, BMC and torsional strength at the shaft compared to their study peers. Similarly, BMC and BSI at the distal radius and bone areas, BMC and torsional strength at radial shaft were 1.7-3.4% greater in women within the highest tertile of daily steps compared to the women with a lower number of daily steps. In men, the differences in studied bone traits were mainly non-significant across the tertiles of daily steps. Statistically significant results presented have p-values of ≤0.05. In conclusion, the genetic heterogeneity in lactase gene or the APOE ԑ2/ԑ3/ԑ4 genetic variation seemed to have little effect on the studied bone traits at the radius and tibia. Instead, the APOE promoter -219T/T and +113C/C alleles were associated with lower cortical bone phenotypes in both genders compared to the G/G carriers. In women, these supposed risk alleles of APOE promoter polymorphisms were also associated with lower total area and torsional strength at the radial shaft when the intake of saturated fat was high. In addition, a high level of physical activity at the age of 9-18 years, but not in younger children, was associated with wider and stronger weight-bearing tibia in both females and males. In adulthood, a higher amount of physical activity measured as daily steps was associated with greater bone cross-sectional area, mineral mass and strength at the calcaneus, tibia and radius in women.
  • De, Swarnalok (Helsingin yliopisto, 2019)
    Potyviral helper component proteinase (HCPro) is a quintessential example of a multifunctional viral protein. Its name comes from two of its earliest identified functions- ‘Helper Component’ involved in aphid-mediated plant-plant transmission of the virus, and cysteine proteinase responsible for its self-cleavage from the rest of the viral polyprotein. HCPro’s best-studied function is its ability to suppress RNA silencing. One of the factors underlying the multifunctionality of HCPro is its ability to interact with a wide range of host factors causing perturbations in several cellular pathways. In this study, interaction of HCPro with the host proteins S-adenosyl-L-methionine synthase (SAMS), S-adenosyl-L homocysteine hydrolase (SAHH), ARGONAUTE 1 (AGO1) and VARICOSE (VCS) was addressed and implications of these interactions in potato virus A (PVA; genus Potyvirus) infection, and potato virus X (PVX)-PVA mixed infection were studied. In this study, HCPro was found to interact with the host methionine cycle enzymes SAMS and SAHH and to inhibit SAMS activity. Disruption of the methionine cycle promoted PVA infection. Methionine cycle plays a crucial role in the smooth running of RNA silencing by providing S-adenosyl methionine (SAM) for methyltransferase hua enhancer 1 (HEN1). Small RNA (sRNA) duplexes, which are methylated by HEN1, are stable and capable to act in RNA silencing, whereas, the unmethylated sRNAs are polyuridylated and targeted to degradation. A blockage in sRNA methylation via HCPro-mediated methionine cycle disruption was proposed to act as a circuit breaker of RNA silencing pathway for the benefit of PVA infection. SAHH was also found to be involved in PVX-PVA synergism. Blockage of the methionine cycle at SAHH, coupled with synergism-specific downregulation of closely associated glutathione (GSH) biosynthesis pathway enhanced PVX genomic RNA accumulation and subgenomic RNA expression. Moreover, depletion of cellular antioxidant GSH was suggested to be the reason behind induction of severe oxidative stress during potex–potyvirus mixed infection. In another line of this study, formation of HCPro-associated high molecular weight (HMW) complexes and their functions were studied. Interaction between HCPro and a WD40 domain containing scaffolding protein VCS was shown to be crucial for formation and stability of HCPro-associated HMW complexes. Importance of HCPro-VCS interaction in governing the assembly of PVA-induced granules (PGs) was demonstrated. This study reinforced the correlation between the PGs and RNA silencing suppression. Interestingly, HCPro, AGO1, VPg and CI were detected in the ribosome-associated HMW-complexes. Association of AGO1 with ribosomes may indicate occurrence of RISC-mediated translational repression as an additional defense mechanism against PVA infection. While, presence of HCPro, VPg and CI therein suggested a putative mechanism by which HCPro derived ribosome-associated HMW complexes might participate in relieving PVA translational repression. Accordingly, co-operation between HCPro, VCS and VPg was shown to act in favor of active PVA translation. Intriguingly, importance of HCPro-VCS interaction was also found to be important in PVA encapsidation. In conclusion this study provides evidence for interaction between HCPro and host proteins SAMS, SAHH, VCS and AGO1 in planta. Furthermore, importance of these interactions are demonstrated to play crucial role in governing various viral processes during PVA infection.
  • Kempe, Riitta (Helsingin yliopisto, 2018)
    The aim in blue fox selection is to improve reproduction traits, fur quality and size. Animal health, welfare, conformation traits or feed efficiency also show genetic variation and can be selected along with these traits. Due to unfavourable changes in blue fox conformation and health traits, there is a need to investigate how the focus in current selection should be changed to improve the situation. In addition to welfare traits, an important new breeding goal is feed efficiency, given that feeds form a major production cost and the inefficient utilization of feed may lead to poor growth and to nutrients being leaked into environment. The main objectives of the thesis research were to estimate genetic variation for new conformation, health and production traits, and to determine their correlation with the production traits currently used in ranking animals for selection. These results are needed to reform the selection programme. Animal assessment and scoring systems for the new traits were created in the thesis research, namely for feed efficiency, body condition (fatness), animal body length, leg conformation, ability to move about and susceptibility to eye infection. While the current emphasis on selection for larger animal and pelt size does improve feed efficiency indirectly, it is unlikely to lead to lower feed intake. Selection for feed efficiency and larger pelts tends to favour fast-growing and fat individuals, simultaneously increasing the feed intake and, hence, feeding costs. Fast growth rate and extreme fatness also pose a risk to blue fox welfare because better growth and larger size (body weight and fatness) often cause leg weakness and impair the ability to move about in less than six-month-old blue foxes. However, no genetic connection was observed between eye health and animal size or fatness, whereas selection for thicker fur density can increase eye infection risk. The use of body length as a selection criterion can open up the possibility to breed well-structured, slim foxes, since such selection does not increase the risk of fatness or susceptibility to eye infection nor does it have unfavourable effects on pelt quality traits. Estimates on the amount of genetic variation in conformation, health and feed efficiency show that these traits are heritable and that genetic improvement through selection has considerable potential to improve the health status and feed efficiency in Finnish blue foxes along with production traits. This requires broadening of current breeding goals to include diverse traits, changing the selection focus to new welfare traits and extending the coverage of national recording and breeding scheme. Keywords: Alopex lagopus, animal breeding, fur animals, heritability
  • Sell, Mila (Helsingin yliopisto, 2018)
    This thesis approaches some of the global challenges of the coming decades, including climate change, biodiversity loss, growing populations, and food insecurity, from a small-scale farmer’s perspective. In Africa small-scale farmers still account for up to 70% of the population, and represent the poorest and most vulnerable group to these challenges. They are, however, a heterogeneous group with various problems and needs. Sustainably improving their situation will require context-specific solutions developed through an innovation process, in which local needs and voices are heard and taken into consideration. Active participation in the Innovation System requires innovation capacity and empowerment. This is especially crucial for women farmers, who face a number of additional constraints compared to their male counterparts. This difference in constraints is commonly referred to as the gender gap. There is a gender gap in access to resources such as land, inputs, labour and credit, but also in access to education, training, and rights. Supporting small-scale farmers, especially women farmers, can positively influence productivity and contribute to better wellbeing of whole families. The aim of this thesis is to identify and understand the determinants of some of these gender-related constraints, as well as to discuss some of the possible pathways towards more equal and sustainable systems. It consists of three papers, each describing an empirical study of the challenges affecting small-scale farmers, from a particular approach. Both quantitative and qualitative methods are used. Triangulation allows us to see both context-specific cases, but also the many common trends and underlying rules that drive these processes. Papers I and II are based on a large-scale household survey from Uganda, for which data was collected from 1440 households. The analyses use econometric modelling to identify patterns and constraints of women farmers. Paper I focuses on characteristics of farm households associated with women empowerment, a methodology inspired by the Women Empowerment in Agriculture Index (WEAI). We use decision-making as the main determinant to define empowerment. The results suggest that empowerment is significantly influenced by age, but also by the size of the household, and particularly the number of children under five. This is related to the time burden that household work puts on women. Another significant variable is educational equality, suggesting that the larger the difference in education between the spouses, the lower the level of female empowerment. Paper II uses a stochastic frontier analysis (SFA) to compare the efficiency of women farm managers, to that of male or jointly managed farms, and to identify the determinants of inefficiency of women managers. We find a statistically significant difference in efficiency between the different groups – women managing plots less efficiently than their male counterparts or the jointly managed plots. Also in this case we find that household-related time burden has negative consequences. Women working outside the household, on the other hand, was positively associated with efficiency. We argue that supporting women to participate more actively in income generating activity may have a positive impact on household wellbeing. Paper III describes a participatory pilot study in Ethiopia, in which an Innovation Platform (IP) was established. The paper evaluates the IP methodology based on qualitative data collected through two surveys, focus group discussions, IP meeting reports and key informant interviews. The study analyses the IP activity from a co-creation approach, focusing on the experiences of the participants. We found that participating in the innovation system, through the IP tool, allows especially women farmers to be actively involved. They all reported that their role as communicators and model farmers in the community was strengthened. Using IP methodology as a tool of the extension system could potentially benefit women empowerment as well as livelihoods. The three papers all focus on issues relating to food security, sustainable productivity, livelihoods and wellbeing of small-scale farmers in Africa, although the individual studies have different methodologies and approaches. The summarising chapter of the thesis takes all three studies and includes them under a joint theoretical framework. The research questions of the overall thesis therefore take a holistic approach, and attempt to respond to the following questions: 1. What are the key aspects or characteristics of women empowerment among small-scale farmers? 2. How do these characteristics relate to the productivity and efficiency of farming practices of men and women? 3. How can participation in the innovation processes support small-scale farmers’, particularly women farmers’, empowerment, productivity and visions for the future? 4. How can these approaches be used to develop pathways towards sustainability? The results are formulated as different pathways towards the overall goal of improving small-scale farmers’ wellbeing. The aim is creating sustainable farming systems that increase productivity while improving equality and empowerment. The key promising pathways identified include: increasing education, developing opportunities for non-farm income generating activities, supporting women farmers’ market-based agriculture, and supporting equality and women’s empowerment through co-creation and Innovation Platform methods. Education of women and girls is essential in order to reach the overall goal. However, increasing women’s empowerment will also require educating men and boys, as a gender gap in education was found to have negative implications. It will be important to focus on different types of education, at different levels. In some cases technical extension training is more relevant than actual formal education. But good basic knowledge is a pre-requisite also for this, and finding ways to keep girls in school is considered a central pathway. It is an issue related to equality and empowerment. Empowered girls and women are also more likely to get involved in various non-farm income-generating activities outside the household, which in turn is likely to increase wellbeing. Supporting women in developing market-oriented agriculture is also important. Farmer groups, especially women farmer groups, may have an important role to play. One method for supporting these groups is using Innovation Platforms. Therefore, one of the main recommendations of this thesis is a methodological one. It is a pathway suggesting integration of Innovation Platforms into current extension systems. This will allow different stakeholders to collaborate and participate in co-creation of local solutions to local problems.
  • Saarinen, Merja (Helsingin yliopisto, 2018)
    Life cycle assessment (LCA) is the most used methodology for assessing the environmental impacts of products, such as food. Comparison between products should be based on a common functional unit (FU). The FU describe a function or functions of the product against which life cycle impacts should be related to. For the food products nutritional value is not typically present in currently used FUs. This dissertation develops and analyses ways to link nutritional aspects into LCA of food so that relevant additional information can be achieved compared to the current LCA practice. Its focus is at analysing the applicability of various different FUs at a product and portion level where a primary consumer choice operates. The alternative nutritional FUs developed and analysed are: 1) standardised meals, 2) mass-based FUs for individual nutrients, and 3) the nutrient indexes of products. Altogether 66 food products and 29 lunches consisting of 27 food items were assessed using LCA for climate impact as an impact category. At product level, a product group specific approach is emphasized, and protein source foods are highlighted as an example of a product group. According to the results the use of a nutrient index based on recommended nutrients as an FU is proposed to be, currently, the most suitable general methodology for including nutrition in a food LCA on a product scale. The index which consists of nutrients to be limited is proposed to be combined with these indexes while defining sustainable products. Mass-based FUs for individual nutrients is, instead, proposed to be applied only restrictedly in the cases of scare but essential nutrients which exist only in a few food products. Additionally, the use of the standardised portion as an FU provides relevant additional information related to the LCA of individual products, such as meat or vegetables, which alone are not able to provide adequate nutrient composition intake. The plate model is well-known and the visual element makes it easy to understand. In the common scientific and popular discourse, the message has been clear when reasoning for sustainable food consumption: one should avoid animal-based foods, particularly beef because beef has by far the greatest environmental impact. According to the results of this dissertation, however, particularly beef, in addition to for example hemp seeds, would benefit from the inclusion of nutrition criteria in food LCA on a product scale. The same issue can partly be seen at a more general level also on the portion scale assessment. According to the assessment on the portion scale, the choice of salad also makes a substantial difference from the point of view of the climate impact if grown in greenhouses. The choice of starch, even rice, was without major implications in the context of the plate model. Based on the results, the whole picture of the climate impact can be received, only, by including into the assessment 1) the production processes that lead to eatable products and by the inclusion of 2) the combination the functions of the food groups, which have different specific roles in the nutrition. In summary, nutrition should be taken into account in versatile ways in the food LCA. Each assessment pattern assessed in this dissertation has its own strength, and vice versa none of the methods can provide an all-inclusive understanding.
  • Lampela, Maija (Suomen Metsätieteellinen seura, Helsingin yliopiston Maatalous-metsätieteellinen tiedekunta, Itä-Suomen yliopiston Metsätieteiden osasto, 2018)
    Tropical peatlands of South East Asia are major hotspots of biodiversity and great carbon stores. The main peat forming ecosystem is tropical peat swamp forest (TPSF) growing on top of meters deep peat. Forest degradation by vast scale land conversions and consequent pernicious impacts on the environment have raised an urgent need for conservation and restoration. This dissertation concentrates firstly on the peat soil properties, ground surface microtopograhy and vegetation patterns of the natural TPSF, and secondly on the vegetation restoration, i.e. reforestation of degraded tropical peatland. In the studied natural TPSF type, the forest floor can be characterized as an irregular continuum of less common hummocks and more abundant flat low-lying surface where most of the peat surface is not inundated for most of the year. Unlike in the boreal and temperate peatlands, the ground surface microtopography had no regular patterning. The surface peat structure and chemistry had differences in relation to the surface microtopography. Higher surfaces had higher nutrient concentrations and saplings and trees were concentrated on higher surfaces whereas seedlings emerge in all ground surface elevations. In the open degraded former TPSF area we tested 21 native tree species for their potential for reforestation in a planting experiment. We increased the knowledge on the species’ early stages flood and drought tolerances, species’ suitability for different conditions in reforestation areas and suitable species-specific seedling height for planting. For five species with known potential for reforestation purposes we tested the impact of three site preparation treatments, weeding, fertilizing and mounding, on the seedling performance. We analyzed also the effects of wildfires which caught the study area two years after planting. With increased knowledge on both natural TPSF ecology and the seedling experiments on degraded areas, we could specify environmental condition requirements for several tree species for reforestation.
  • Humisto, Anu (Helsingin yliopisto, 2018)
    Nature is a treasury of bioactive natural products that are developed into pharmaceuticals, cosmetics and other industrial applications. Natural products have an impact on all of us, for instance, in the form of antibiotics. Most of the drugs sold today are natural products or their derivatives. However, the need for new natural products has not decreased but is rather increasing. The incidences of certain diseases such as cancers are rising and resistance to treatment is a major problem. Especially prokaryotes and plants produce these intriguing natural products, which display several different bioactivities. Cyanobacteria are photosynthetic prokaryotes that belong to the most prolific sources of bioactive compounds. This study expands the knowledge of cyanobacterial natural products, including their activities, biosynthesis, and mechanisms of action. The University of Helsinki Cyanobacteria Culture Collection was utilized in this study. Cultured cyanobacteria were screened for antileukemic and antifungal activity using cell assays and disk diffusion analyses. Bioactive compounds were identified with spectrometric methods. The screenings revealed several bioactive hits, including antifungal, antileukemic and cytotoxic activities. Novel compound candidates and known compounds from new habitats or genera were found. In addition, novel variants of known compounds were identified. The results from screening were used to select cyanobacterial strains for whole genome sequencing. Genomic analysis was used to identify the biosynthesis gene clusters of the cytotoxic compounds swinholide and scytophycin. In addition, the production of swinholide was confirmed for the first time using axenic cyanobacteria. In the last part of the study, the mechanism of action of hassallidin was determined using cellular assays, imaging, and lipid models (in vitro and in silico). Hassallidin D purified from Anabaena sp. showed cholesterol-dependent lytic activity against eukaryotic cells. The development of a natural product into a drug or other application is a long process, but natural products are needed also in the future. This thesis contributes to this effort by increasing the understanding of several bioactive cyanobacterial natural compounds at both the functional and molecular level.
  • Qin, Nanbing (Helsingin yliopisto, 2018)
    High-producing dairy cows suffer from metabolic stress, particularly during the periparturient period. The high nutrient demand of milk production leaves the animals susceptible to various metabolic diseases after calving. Improving the health and welfare of high-producing dairy cows has been a long-term goal of dairy research and it is critical for the sustainability of the dairy industry. Previous research has suggested that the nutrition strategies during the dry period and early lactation have significant impacts on dairy cow metabolism after calving. Therefore, careful dietary management in the weeks leading up to and immediately after calving is important for dairy cow health and welfare. In this thesis, the cows received two types of dietary management: a prepartal high-energy feeding regimen and a milk fat depression (MFD) feeding regimen in two experiments, respectively. The high-energy feeding provided 130% of the recommended intake of a pregnant dairy cow during the last six weeks before parturition. The MFD diet was achieved by applying either a diet with a conjugated linoleic acid (CLA) supplement (cis-9, trans-11 and trans-10, cis-12 CLA; 10–15 g/d for each) or a high-starch diet (202 g/kg of dry matter) with polyunsaturated fatty acid (PUFA) supplement (40 g/kg of dry matter; mixture of sunflower oil and fish oil in a 2:1 ratio). The primary objective of this thesis was to investigate the effects of the dietary management on the energy metabolism and insulin resistance of dairy cows. Moreover, the study was aimed to investigate the potential molecular mechanisms underlying maternal insulin resistance and the physiological adaptation of dairy cows during the periparturient period based on analyses of lipidome and transcriptome. The prepartal high-energy feeding of dairy cows affected the lipidomic profiles in the liver and adipose tissue during the periparturient period. The diet effect was particularly evident in sphingolipid concentrations. The high-energy diet increased the hepatic total sphingomyelin concentration at both 1 wk prepartum and 1 wk postpartum. In the adipose tissue, the total ceramide concentration was elevated by the prepartal high-energy feeding at 1 wk prepartum. Of these sphingolipids, the highest sensitivity to prepartal energy levels was displayed in the adipose tissue by several ceramide subspecies and in the liver by sphingomyelin subspecies that contained a long-chain or very long chain fatty acids. In addition, the high-energy feeding elevated the concentrations of various phospholipid and lysophospholipid classes in the liver and altered the time-related patterns in the concentrations of various phospholipid classes in the adipose tissue. Analysis of the hepatic gene expression revealed that prepartal high-energy feeding promoted hepatic lipogenesis at 1 wk prepartum by upregulating the transcription of the thyroid hormone responsive gene and the liver X receptor/retinoid X receptor activation pathway. The hepatic inflammatory status was potentially reduced by the prepartal high-energy feeding at 1 wk prepartum, as suggested by the downregulation of the acute phase signalling pathway and the decreased transcription of the pro-inflammatory genes interleukin 1 and nuclear factor kappa B subunit 1. Both the MFD-inducing diets improved the energy balance and decreased plasma levels of non-esterified fatty acids and beta-hydroxybutyrate during early lactation. The CLA-supplemented diet reduced the plasma levels of ceruloplasmin and bilirubin at wk 3 of lactation, suggesting an attenuated inflammation status. However, the high-starch and PUFA-supplemented diet had the opposite effect by increasing the levels of ceruloplasmin and bilirubin at wk 15 of lactation. Both the CLA-supplemented diet and the high-starch and PUFA-supplemented diet downregulated lipolysis in the adipose tissue at wk 3 of lactation by reducing the transcription of hormone-sensitive lipase and fatty acid binding protein 4. The decreased lipolysis resulted in increased lipid deposition in the adipose tissue during early lactation, reflected by the increased transcription of perilipin 2. Lipogenesis in the adipose tissue was potentially increased by the high-starch and PUFA-supplemented diet at wk 15 of lactation. In contrast, the CLA-supplemented diet had no effect on lipogenesis at both wk 3 and 15 of lactation. The CLA supplement likely affected lipid metabolism in the adipose tissue through the regulation of insulin sensitivity, as the diet affected gene expression related to the insulin signalling pathway, the inflammatory response and ceramide metabolism. In contrast, the high-starch and PUFA-supplemented diet had little or no effect on these insulin-related pathways and therefore it may have regulated lipid metabolism in the adipose tissue through other pathways. In conclusion, increasing prepartal energy intake (130% of the energy requirement for a pregnant dairy cow) did not impair the normal liver function and insulin sensitivity of dairy cows near calving. Moreover, this diet attenuated the hepatic inflammatory status during the final stage of pregnancy. Both the CLA-supplemented diet and the high-starch and PUFA-supplemented diet potentially reduced the cows’ metabolic stress by decreasing the necessity to mobilize body reserves. However, these two MFD-inducing diets may have had different effects on the inflammatory status of dairy cows. The CLA supplement may attenuate systemic inflammation during early lactation, while the high-starch and PUFA-supplemented diet may have exacerbated inflammation during the later lactation stages.
  • Xu, Yan (Helsingin yliopisto, 2018)
    Fava bean is a good source of plant protein that is increasingly gaining attention due to its health benefits and sustainability. However, the addition of fava bean flour or protein concentrate at high concentrations to food products may result in an unsatisfying texture. Therefore, texture modification of the fava bean matrix is essential to improve its usability in various food systems. Microbial exopolysaccharides (EPS) are effective texture modifiers, with lactic acid bacteria (LAB) being widely used in the food industry to produce them. In this thesis, EPS were produced in situ from sucrose by LAB during the fermentation of fava bean flour or fava bean protein concentrate (FPC), and their texture modification effects on fava bean matrix were evaluated. Leuconostoc pseudomesenteroides DSM 20193 and Weissella confusa VTT E-143403 were found to be good dextran producers in fava bean matrix. With the same starter, sucrose addition strongly increased paste viscosity after fermentation. By separately hydrolyzing the fermented paste with dextranase and levanase, this increase was demonstrated to be primarily driven by dextran. The gel-strengthening ability of EPS was revealed by dynamic oscillatory rheology analysis, with obvious elasticity increases in sucrose-enriched pastes after fermentation. Dextrans produced by Ln. pseudomesenteroides DSM 20193 and W. cibaria Sj 1b showed considerable gel-strengthening ability. Two mechanisms of degradation for raffinose family oligosaccharides (RFO) were established in this thesis, involving plant-derived α-galactosidase and microbial levansucrase (LSR). In fava bean flour, RFO were preferentially degraded by endogenous α-galactosidase, producing galactose and sucrose that could be further used for EPS synthesis. In the absence of endogenous α-galactosidase, LSR could act on RFO, forming melibiose, manninotriose, and manninotetraose. A joint function of endogenous α-galactosidase and microbial LSR in RFO degradation was also observed. Texture evaluation of fermented FPC pastes revealed higher firmness, consistency, cohesiveness, and index of viscosity in sucrose-enriched pastes. Proteolysis of fava bean protein was very weak after fermentation, thus contributing less to texture modification of FPC pastes than did EPS. Confocal laser scanning microscopy of fermented fava bean protein showed more concentrated protein aggregates in dextran-enriched pastes. The study of fava bean protein-dextran interactions indicates the importance of intermolecular interactions between these two polymers in determining the rheological properties of the system. During acidification, dextran stabilized the network of fava bean protein through intermolecular interactions. Conjugation of dextran to fava bean protein through the Maillard reaction decreased both viscosity and gel elasticity during protein gelation. The molar mass and conformation of dextrans affected their behavior in the protein system, especially during protein gelation. This thesis shows for the first time the feasibility of connecting EPS production by LAB to the fermentation of fava bean matrix, and identifies two promising dextran producers for use in this matrix. Analysis of the microstructure of fava bean protein with dextran and fava bean protein–dextran interactions clearly showed the role of dextran in the protein network. Furthermore, the results indicate that different EPS producers may allow texture tailoring of the fava bean matrix, which may contribute to the development of novel plant protein-based food or meat substitutes.
  • Kaarakka, Lilli (Helsingin yliopisto, 2018)
    Human-induced disturbances may change vegetation and carbon (C) and nitrogen (N) processes in the forest floor and the soil beneath it. The aim of this dissertation was to study the effects of physical and chemical disturbance on boreal forest soil and vegetation. Two contrasting soil-affecting treatments – stump harvesting and sprinkling infiltration – were studied as case studies. Sprinkling infiltration alters the chemical composition of forest soil, whereas stump harvesting results in changes especially in the physical structure of the forest soil. The effects of stump harvesting on forest soil surface disturbance, C and N pools and mineralization rates, understory vegetation, seedling growth and coarse woody debris (CWD) were studied in Norway spruce (Picea abies (L.) Karst.) stands located in Central and Southern Finland. The results of this study indicate that stump harvesting causes soil surface disturbance, and mixing and relocation of organic matter in the soil profile, which in turn is reflected to the soil C and N dynamics. Furthermore, stumps, coarse roots and fine coarse roots represent a significant portion of the stand CWD, belowground biomass and nutrients. The effects of sprinkling infiltration on forest soil, tree growth and understory vegetation and their respective recovery were studied in an experimental stand that had been infiltrated with surface water in order to produce artificial groundwater. Sprinkling infiltration had short-term effects on tree growth and long-term effects on soil chemical processes and understory vegetation. In conclusion, sprinkling infiltration is an environment altering treatment, which based on the findings of this study, can affect ecosystem recovery. The results of this study demonstrate that disturbances affect the function and structure of forest soil and these changes can persist on the surface of the soil in the organic layer and deeper in the mineral soil. Furthermore, this dissertation highlights the need for long-term perspectives in ecosystem management and planning.
  • Sietiö, Outi-Maaria (Helsingin yliopisto, 2018)
    The boreal forests are significant sinks for carbon, and the majority of the carbon present in boreal forests is stored in the soils. Especially in the organic layers of the boreal forest soils, a significant amount of the carbon is stored as complex polymers, which are rather stable and have a long residence time. In addition, these soils are considered to be nutrient poor since important nutrients, such as nitrogen and phosphorus, are complexed with soil particles or stored in organic forms, which are inaccessible to the plants. For acquiring nutrients from the complex substrate, plants form mutualistic associations with fungi. In boreal forest ecosystems, where above-ground vegetation is dominated by coniferous trees, shrubs and mosses, the most common fungi associated with plant roots are ectomycorrhizal and ericoid mycorrhizal. In return for the enhanced water and nutrient uptake, the plants provide energy to their fungal symbionts in the form of recently photosynthesized carbon. As it is predicted that the amount of atmospheric CO2 levels will rise and the climate will warm, the growing season will be extended in the boreal zones and the input of photosynthetic C from the plants to the soil will increase. This increase in the input of photosynthates from the plants can accelerate the below-ground processes and enhance the degradation of the older, stable soil organic matter through a phenomenon called the “priming effect”. Thus, a more thorough understanding of the dynamics of plant-fungal interactions and their importance to the functioning of the whole boreal forest ecosystem is essential when predicting ecosystem level responses to the changing environment. This PhD thesis aimed to enlighten the effect of plant-derived photosynthetic carbon to the fungal community structures and soil organic matter decomposition. Two studies of this thesis are based on a laboratory scale microcosm experiment, and the third study is based on a multiyear field experiment. Fungal community structure was assessed using high throughput sequencing. In addition, the first study provided new insights on the root-associated fungal communities which utilized photosynthates directly from the plant, as well as their host preference via a stable isotope probing technique. The common boreal forest plants, ericoid shrubs Calluna vulgaris (common heather), Vaccinium myrtillus (bilberry), and Vaccinium vitis-idaea (lingonberry), and the conifer Pinus sylvestris (Scots pine) shaped their root and surrounding soil associated fungal communities differently from each other, while they also shared many fungal species. In addition, the ericoid shrubs and their associated microbes had different effects on the soil chemistry and enzymatic activities compared to the conifer P. sylvestris. The results from the laboratory scale experiment described in the first two studies of this thesis indicate that ericoid plants have an important influence on fungal community structures and processes in boreal forest soils. The manipulation of the carbon flow from the plant to the soil induced moderate changes to the fungal community structure in humus during a three-year field experiment. According to the ecological theory known as the “Gadgil effect”, decomposition should be enhanced when saprotrophic fungi are alleviated from competition with ectomycorrhizal fungi. However, the results of the third study of this thesis did not support the Gadgil theory, indicating that the competitive outcome between the saprotrophic and ectomycorrhizal fungi is substrate dependent and these two fungal guilds have preference towards different ecological niches. In addition, the results suggest that the members of the soil microbial community are rather flexible and can adapt to temporary disturbances. This PhD thesis provided further insights into the role of plants in determining the fungal community structure on their own roots and surrounding soils as well as shaping the soil chemical profile. The results underline that for predicting how the changing climate affects soil processes in the boreal forest ecosystem, more knowledge on plant microbe interactions and their impact on soil processes is needed.
  • Santalahti, Minna (Helsingin yliopisto, 2018)
    Boreal forest soils store a significant amount of carbon and function as a terrestrial net sink in the global carbon cycle. Soil microbes perform essential ecological functions by cycling nutrients and decomposing organic matter. Fungi are the predominant decomposers and central to the turnover of carbon and nitrogen in boreal forest soils. The production of various extracellular enzymes allows fungi unique access to soil organic nitrogen that is bound to recalcitrant soil organic matter. As nitrogen is typically the growth limiting factor, almost all plants in boreal areas are mycorrhizal. This mycorrhizal symbiosis improves the access of plants to nitrogen, nutrients and water in the soil, and in turn, plants deliver large quantities of photosynthetically fixed carbon to mycorrhizal fungi. The main objectives of this thesis were to investigate soil fungal communities and some of their functions seasonally and vertically in different soil horizons and in relation to the disturbances of forest fire and reindeer grazing. The studies were conducted in three main ecosystem stations in Hyytiälä, Sodankylä and Värriö, in southern and northern boreal Scots pine forests. The fungal communities and some of their functions were analyzed using high-throughput sequencing technology (454-pyrosequencing) combined with the identification of potential gene functions using the GeoChip 4.0 microarray and extracellular enzyme activity measurements. The results showed that fungal communities were in general species-rich across the studied areas, and the species richness was higher in southern compared to northern boreal forest soils. Fungal communities were clearly stratified by soil horizons. Saprotrophic and ascomycete fungi dominated the upper most litter horizon, whereas the abundance of ectomycorrhizal and basidiomycete fungi increased in lower organic and mineral soil horizons. Fungal communities shifted drastically and rapidly in time, as saprotrophic fungi dominated the communities in late winter and were quickly replaced by ectomycorrhizal fungi at the beginning of the growing season. Fungal communities were remarkably stable during the entire growing season and were dominated by ectomycorrhizal basidiomycete fungi. Forest fire altered fungal communities and their potential gene functions significantly. Alpha diversity was highest in the recently burned site (two years after fire), and ascomycete and saprotrophic fungi dominated the communities. The diversity decreased with time since fire, with basidiomycete and ectomycorrhizal fungi dominating the communities in the older burned sites. Fungal diversity correlated positively with functional gene diversity, indicating that higher microbial diversity supports higher genetic potential for maintaining crucial biochemical reactions in soils. Reindeer grazing also had a significant effect on soil fungal community structure, the abundance of certain genera and species, and litter degradation related enzyme activities. With longer time scales, grazing may affect litter decomposition through changes in fungal communities and their corresponding enzyme activities. In northern boreal forest soils, fungal communities were, in general, sensitive to the disturbances. The effect was most drastic immediately after the disturbance. However, soil fungal communities were slowly able to adapt to the changing conditions and displayed signs of recovery from the disturbances in the course of around hundred years. Some generalist species were more resistant to the disturbances than others. Many abundant generalist fungi, such as the genera Cortinarius, Lactarius, Suillus and Piloderma were detected in all studied successional stages, treatments and sites, although their relative abundances varied. Successional shifts were also observed among ectomycorrhizal families, as fungi from the family Atheliaceae dominated the communities in young and mid-aged forests sites, and fungi from the family of Cortinariaceaea increased in abundance over time and dominated in the old-growth forest sites.
  • Himanen, Katri (Helsingin yliopisto, 2018)
    The artificial regeneration of Norway spruce (Picea abies (L.) Karst.) in the Nordic countries relies on planting containerized seedlings originating from seeds collected from either seed orchards or forest stands. The aim of this thesis is to investigate the effect of seed quality attributes on seedling production and to study whether it is possible to enhance germinability and seedling health through seed soaking treatments. The variation in seed quality among individual trees and clones and the components of seed weight variance are also studied. Commercial seed lots were screened for microbes and the effect of soaking treatment on microbial abundance was analyzed. The three seed lots contained some pathogenic fungi, but most fungi found were saprophytic. The seed lots differed in their likelihood to suffer from damping-off when germinated in water agar medium but not in peat. With current production methods seed-borne fungi do not have a great impact for seedling health, but altering for example the growing media may increase their importance. Seedling quality declined with increasing emergence time in an experiment on 1-year-old seedlings in the nursery, thus emphasizing the importance of fast germination. Seed soak-sorting hastened the emergence and increased seedling size more in 1.5-year-old containerized seedlings compared to the 1-year-old seedling crop in addition of decreasing the proportion of cull seedlings. The proportion of full seeds varied between individual trees and clones in cones collected from a forest stand and from a seed orchard. The average seed weights differed between trees or clones, but intracone variation was the greatest source of seed weight variance. This indicates that weight-based seed sorting may have a smaller impact on the genetic diversity of seed lots than previously thought. Seed and seedling producers as well as society have different preferences for seed quality attributes and different tools for quality management.
  • Manni, Katariina (Helsingin yliopisto, 2018)
    Beef production in Finland is mostly based on dairy breeds. To compensate for the lack of domestic beef, slaughterhouse pricing favours lean and heavy carcasses. Higher carcass weights increase the probability of increasing fatness. It is necessary to control fatness because consumers generally favour low-fat products. In addition, excessive fat accumulation decreases the efficiency of feed utilization. High-fat carcasses are undesirable for the meat industry because the value of fat is low compared with that of red meat. Consequently, slaughterhouses have implemented price penalties for fat carcasses. For these reasons, carcass fat score is an important production parameter that affects the profitability of farms and the entire beef chain. On the other hand, very low-fat carcasses may decrease the eating quality of the meat. Thus, the target is to produce heavy low-fat carcasses without impairing eating quality of the meat. There is need to establish beef production methods to satisfy demand for such carcasses. One way to reduce carcass fatness and improve feed conversion could be to utilize steadily or periodically restricted energy intake and the ability of animals to exhibit compensatory growth. The main objective of this thesis was to elucidate the effects of different restricted energy intake strategies on performance of growing dairy bulls, especially growth rate, feed efficiency, carcass fatness and meat quality. Energy intake was restricted by restricting concentrate or total diet dry matter (DM) intake (DMI), either periodically or during the whole growing period. The target was to achieve steady, increased or de-creased growth patterns with diets based on grass silage and barley grain. The objectives of the first experiment were to determine the effects on animal performance and meat quality when energy intake and growth rate were manipulated by controlling energy intake through changing barley allowance and allocation and offering grass silage ad libitum. Barley allocation regimes were steady, increased and decreased at two concentrate intake levels, where barley as a proportion of DM was either 0.23 or 0.43. Higher energy intake increased live weight gain (LWG). Over the total growing period, periodic energy intake did not affect LWG. Effects on feed efficiency were not found. Higher energy intake did not affect carcass fatness, but periodic energy intake decreased it. Higher energy intake increased meat fat content and tenderness. Periodic energy intake reduced tenderness compared with steady energy feeding. The responses to different energy feeding strategies demonstrated that there were no major effects on performance of animals. Observed effects on meat quality were minor and one explanation may be low carcass and meat fat content in all treatments. The objective of the second experiment was to determine the effects on animal performance when growth rate was manipulated by controlling energy intake through changing total diet DMI. The treatments consisted of four feed allocation regimes: steady, restricted, increased and decreased energy intake. Restricted energy feeding was conducted by restricting DMI by 20% of the intake in the steady feeding treatment. In the increased and decreased treatments, the DMI was restricted similarly but either during the early or late part of the growing period. Average barley proportion of DMI was 0.42 and when DMI was not restricted, silage was offered ad libitum. Restricted feeding strategies decreased LWG and increased the number of growing days required to reach the same carcass weight. Compensatory growth was recorded. There were no significant differences in average feed efficiency attributable to the treatments over the total experimental period. Restricted DMI decreased carcass fat score. The results indicated that silage intake ad libitum and when supplemented with concentrate resulted in the most effective beef production but it also increased carcass fat score. The objective of the third experiment was to determine the effects on animal performance when growth rate was manipulated by controlling energy intake through changing concentrate proportion in total mixed ration. The treatments comprised four feed allocation regimes, which were steady, restricted, increased and decreased energy intake. Barley proportion of DM was 0.30 in the steady feeding treatment. When energy intake was restricted, barley was removed from the diet. When barley was supplemented in the diet during the early or late part of the growing period, its pro-portion on a DM basis was 0.60 and 0.58, respectively. There was a trend of increased LWG by increasing energy intake. When comparing increased and decreased energy intake, carcass fat score increased and decreased, respectively. Energy intake strategies had no effect on feed efficiency over the whole growing period. Although good quality grass silage as a sole feed could support moderate to high levels of performance of growing cattle, including barley in the diet further improved the performance of the animals. The results of this thesis confirm that increasing energy intake is a feasible method for increasing growth rate and shortening the growing period of dairy bulls, but it also increases carcass fatness. The responses to periodic energy intake demonstrated the great ability of growing bulls to adapt to different kinds of feeding regime without ma-jor effects on performance. However, it may reduce carcass fatness. This provides flexibility in selecting feeding strategies based on feed availability and prices, resulting in potential benefits to the economy of beef production. However, when targeting effective rotation time of beef production, high energy feeding during the entire growing period is required. Different feeding regimes had no major effects on meat quality, but did highlight the challenge of improving beef quality through modifying the diet.

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