In this report, the washing efficiency of chemi-thermomechanical pulp (CTMP) from Norway spruce (Picea abies) was investigated when adjusting the temperature and pH during washing as well as implementing different number of wash steps. Concurrent effects of having a high pH and temperature were also examined. CTMP pulp has many uses, one of which is for the manufacturing of packaging board. Lately, this end product has seen a precipitous increase due to the increasing demand of an environmentally friendly alternative within the food packaging sector. A notorious problem associated with all mechanical pulps is how extractives are to a large extent still present after the pulping process, especially unsaturated lipids which are subject to oxidation. This results in the formation of odorous aldehydes that can be easily transferred into the food product, thus contaminating it by altering the perception of taste and odor. This is a frequent problem faced by the status quo liquid board industry. Washing is thus employed late downstream to lower the final wood resin content. Here, available literature has been collated for some basic introductory subjects such as softwood anatomy, wood resin and structures. All of this is described with a focus on softwood, leading up to a thorough breakdown of P. abies. Mechanical pulping and relevant deresination methods for CTMP production are also described, including washing. The objective of this thesis is to evaluate the trends of the final resin concentration as the chosen parameters are altered during washing. The pulp was provided by Rottneros Mill and their industrial process was simulated by using a Büchner funnel for washing. A Soxhlet extractor was used for determining the final extractive contents. It was found that the implementation of additional wash steps reduced the final resin content (1–4 wash steps). The same was found with increasing temperature (60, 70, 80 and 90 °C). The implementation of a fourth wash step seemed to be more efficient at higher temperatures. No conclusions could be drawn from altering the pH due to scattered data points with high uncertainties (pH 7, 8 and 9). The results are limited in terms of significance and are also subject to bias. / I denna rapport undersöktes tvätteffektiviteten av kemitermomekanisk massa (CTMP, chemi-thermomechanical pulp) tillverkad från gran (Picea abies) och hur den påverkas vid justeringar av temperatur, pH och antal tvättsteg. Ytterligare undersöktes förekomsten av eventuella samverkande effekter vid högre temperatur och pH. CTMP-massa har många användningsområden, däribland vid produktion av vätskekartong. På sistone har efterfrågan av vätskekartong ökat markant som ett svar på en allt större strävan efter ett mer miljövänligt alternativ inom matförpackningssektorn. Ett välkänt problem associerat med mekanisk massatillverkning är den stora mängden exktraktivämnen som kvarhålls i den färdiga massan. En viss del av dessa extraktivämnen utgörs av fleromättade fetter vilket är benägna att genomgå oxidation. Detta leder i sin tur till bildandet av flyktiga aldehyder som kan föras vidare till matprodukten och ge dem förändrad smak och lukt; ett problem som dagens vätskekartongproducenter står inför. Tillgänglig litteratur har sammanställts, där en inledande teoridel beskriver koncept såsom anatomi, strukturer och extraktivämnen hos barrved. Teoridelen övergår därefter till att ge en mer detaljerad beskrivning av P. abies och dess extraktivinnehåll. Ytterligare beskrivs mekanisk massatillverkning över lag och metoder för att eliminera extraktivämnen under produktionen av CTMP-massa (inklusive tvättning). Syftet med detta examensarbete är att utvärdera de trender i den slutliga extraktivhalten då de valda parametrarna justeras under tvättning. Massan tillhandahölls av Rottneros Bruk och deras tvättningsprocess simulerades med hjälp av en Büchner-tratt. En Soxhlet-extraktor användes för att utvärdera den slutliga extraktivhalten. Det visade sig att vid varje insättning av ett ytterligare tvättsteg (1–4 tvättsteg) gav en lägre extraktivhalt hos CTMP-massan. Desamma gällde vid ökande temperatur (60, 70, 80 and 90 °C). Implementering av ett fjärde tvättsteg tycks vara mer effektivt vid högre temperaturer. Det kunde dock inte dras några slutsatser huruvida pH påverkade tvättningen då dessa mätvärden fick stor spridning med höga osäkerheter (pH 7, 8 och 9). Resultaten besitter begränsad signifikans och kan även ha blivit utsatta för bias.

The thesis deals with the ecology of lichens in two contrasting types of forest, epiphytic lichens in old Picea abies forest of the fi re-refugia type and epigeic as well as epixylic lichens in a successional sequence of fire- susceptible Pinus sylvestris forests. Results in five separate papers form the basis for a discussion of general patterns of dispersal, succession and life strategies in lichens. The study sites were located in Medelpad and Väs­terbotten, in the central and northern part of Sweden, respectively. Special attention has been paid to the rare, pendulous, spruce-1ichen Usnea longissima and the coexisting lichen species. U. longissima is largely restricted to north-facing hill slopes covered with old, mesic spruce forest that is characterized by a very long continuity not disturbed by fire. A mar­ked decline in the number of sites with U. longissima was found. The decline was mainly due to the effect of different forestry practices as the species is very sensitive to environmental disturbances. The epiphytic lichen vegetation of six tree species occurring in the spruce forest is described. Clear successional trends with increasing tree size were • obtained for Alectoria sarmentosa, Bryoria fuscescens coll., B. nadvornikiana, Usnea filipendula' and U. subflorida'na, to a lesser extent for Bryoria capii-“" laris while U. longissima had no relationship to tree size or age. TTstudy of the litterfall of macrofragments of epiphytic lichens showed that thallus fragments were dispersed throughout the year with late autumn, winter and early spring as the most critical periods. It is suggested that dispersal through thallus fragmentation is more important in fruticose than in foliose species and that U. longissima has a shorter range of propagule transport than the other species of Alectoria, Bryoria and Usnea studied. The latter proposition was supported through a study of the horizontal patterns of lichen occurrence in the spruce forest. It is shown that the diversity in ground vegetation, after an initial in­crease, declines with succession in the pine forests. A mechanism of succes­sion in ground vegetation is presented which suggest that variations in habi­tat heterogeneity, i.e. the diversity of substrates caused by the initial dis­turbance and the stand development, largely determines diversity changes dur­ing succession. Trends of increasing thallus size, increasing size of asexual reproductive propagules and increased competitive ability with succession formed the basis for recognizing three types of strategies in Cladonia» It is concluded that lichens have features that are compatible with the r-K continuum and that they are variously adapted to both the stability of the substrates and that of the forest as a whole. / <p>Diss. (sammanfattning) Umeå : Umeå universitet, 1983, härtill 5 uppsatser</p> / digitalisering@umu

In 1982, several rectangular openings were cut in a 100 year old sub-alpine Norway spruce forest stand to initiate regeneration at the Lusiwald site at Davos, Switzerland. The openings on the steep, north-facing slope created rapid changes to the environment of the border trees. Growth reactions of these border trees were compared and analysed with reference trees from the adjacent closed canopy stand in 1997. The radial growth pattern of the two data sets differed within the 14-year period since the openings were cut; the border trees showed growth releases. The growth reaction at the stem base was larger than at breast height. Changes in wind exposure may have influenced border trees to adapt their root systems. Sub-alpine Norway spruce stands aged around 100 years, which are usually considered slow-growing on a north aspect, still seem capable of reacting to greater resource availability such as sudden light changes.

<p>The Holocene spread of <i>Picea abies</i> in Scandinavia provides an excellent opportunity for detailed study of the dynamics of tree spread and population expansion. Early- and mid-Holocene macrofossil evidence for the presence of <i>Picea abies</i> in Scandinavia has questioned traditional interpretations of the timing and direction of its spread. This study aims to determine the pattern of the spread of <i>Picea abies</i> in Scandinavia from pollen and other data, to evaluate the significance of possible early outpost populations and to deduce possible factors that influenced the spread and population expansion of <i>Picea abies</i> in Scandinavia. </p><p>Palaeoecological investigations were carried out on the sediments of four small lakes in central Sweden to gain detailed insight into the dynamics of the spread. Holocene pollen diagrams with independent dating control were collected from Fennoscandia and adjacent areas to compare the timing of selected features of the <i>Picea abies</i> pollen curve. Computer models were used to test possible scenarios for the spread and <i>Picea abies</i> population expansion. </p><p><i>Picea abies</i> entered the Scandinavian peninsula from the east at different times and by different pathways. Early-Holocene outposts can be discerned in pollen records from northwest Russia, eastern and northeastern Finland for the time before 9000 cal. BP. Pollen records from Sweden and Norway indicate small <i>Picea abies</i> populations after 8000 cal. BP. The mid to late-Holocene spread, which superficially resembles a front-like pattern, may in fact represent a wave of expanding populations. Disturbance through fire and human activity did not significantly influence the pattern of the spread. Changing climate parameters, slow adaptation and gene flow through seeds and pollen have to be considered as possible explanations for the late spread of the tree. Population dynamics and propagule pressure are likely to be important factors that shaped the spread of <i>Picea abies</i>.</p>

<p>The reproductive organs of conifers and angiosperms differ in morphology in several fundamental respects. The conifer Norway spruce <i>(Picea abies)</i> form pollen and seed cones from separate meristems whereas angiosperms bear bipartite flowers with sepals and petals surrounding two inner whorls of stamens and carpels. Despite these differences in morphology this thesis present data to suggest that reproductive development in conifers and angiosperms is regulated by a similar molecular mechanism. This implies an evolutionary conservation of the major mechanism for reproductive development since the origin of seed plants. </p><p>Flower organ identity in angiosperms is determined by regulatory genes belonging to the MADS-box gene family of transcription factors. This thesis presents the cloning and characterisation of four novel MADS-box genes from Norway spruce<i>.</i> Three of these genes <i>DAL11</i>, <i>DAL12</i> and <i>DAL13 </i>are most closely related to angiosperm B function genes <i>i.e.</i> genes required for petal and stamen development. <i>DAL11</i>, <i>12</i> and <i>13</i> all are specifically active in developing pollen cones, with different temporal and spatial expression pattern. Functional analysis in transgenic Arabidopsis and yeast suggest that the reproductive aspect of the B-function is conserved between conifers and angiosperms. The results also suggest that the B-function in conifers is separated into one shoot identity and one organ identity determinant. </p><p>A fourth gene presented;<i> DAL10,</i> is specifically expressed in vegetative parts of pollen- and seed cones. Phylogenetically <i>DAL10</i> is not closely related to any of the known angiosperm clades, but rather forms a separate clade with other gymnosperm genes, suggesting a gymnosperm specific function. We suggest that the <i>DAL10</i> activity reflects a function in the determination of the reproductive shoot.</p>

The reproductive organs of conifers and angiosperms differ in morphology in several fundamental respects. The conifer Norway spruce (Picea abies) form pollen and seed cones from separate meristems whereas angiosperms bear bipartite flowers with sepals and petals surrounding two inner whorls of stamens and carpels. Despite these differences in morphology this thesis present data to suggest that reproductive development in conifers and angiosperms is regulated by a similar molecular mechanism. This implies an evolutionary conservation of the major mechanism for reproductive development since the origin of seed plants. Flower organ identity in angiosperms is determined by regulatory genes belonging to the MADS-box gene family of transcription factors. This thesis presents the cloning and characterisation of four novel MADS-box genes from Norway spruce. Three of these genes DAL11, DAL12 and DAL13 are most closely related to angiosperm B function genes i.e. genes required for petal and stamen development. DAL11, 12 and 13 all are specifically active in developing pollen cones, with different temporal and spatial expression pattern. Functional analysis in transgenic Arabidopsis and yeast suggest that the reproductive aspect of the B-function is conserved between conifers and angiosperms. The results also suggest that the B-function in conifers is separated into one shoot identity and one organ identity determinant. A fourth gene presented; DAL10, is specifically expressed in vegetative parts of pollen- and seed cones. Phylogenetically DAL10 is not closely related to any of the known angiosperm clades, but rather forms a separate clade with other gymnosperm genes, suggesting a gymnosperm specific function. We suggest that the DAL10 activity reflects a function in the determination of the reproductive shoot.

The Holocene spread of Picea abies in Scandinavia provides an excellent opportunity for detailed study of the dynamics of tree spread and population expansion. Early- and mid-Holocene macrofossil evidence for the presence of Picea abies in Scandinavia has questioned traditional interpretations of the timing and direction of its spread. This study aims to determine the pattern of the spread of Picea abies in Scandinavia from pollen and other data, to evaluate the significance of possible early outpost populations and to deduce possible factors that influenced the spread and population expansion of Picea abies in Scandinavia. Palaeoecological investigations were carried out on the sediments of four small lakes in central Sweden to gain detailed insight into the dynamics of the spread. Holocene pollen diagrams with independent dating control were collected from Fennoscandia and adjacent areas to compare the timing of selected features of the Picea abies pollen curve. Computer models were used to test possible scenarios for the spread and Picea abies population expansion. Picea abies entered the Scandinavian peninsula from the east at different times and by different pathways. Early-Holocene outposts can be discerned in pollen records from northwest Russia, eastern and northeastern Finland for the time before 9000 cal. BP. Pollen records from Sweden and Norway indicate small Picea abies populations after 8000 cal. BP. The mid to late-Holocene spread, which superficially resembles a front-like pattern, may in fact represent a wave of expanding populations. Disturbance through fire and human activity did not significantly influence the pattern of the spread. Changing climate parameters, slow adaptation and gene flow through seeds and pollen have to be considered as possible explanations for the late spread of the tree. Population dynamics and propagule pressure are likely to be important factors that shaped the spread of Picea abies.

The aerial plant body is derived from undifferentiated cells in the shoot apical meristem that in Arabidopsis thaliana is active throughout the plant life cycle. Upon transition to flowering the activity of the meristem is altered and the meristem starts to produce secondary inflorescences and floral meristems instead of leaves. Both the activity of the meristem and the decision of when to flower are processes strictly regulated by several mechanisms. In this thesis I describe the function of two genes that are active in the regulation of meristem function and in the regulation of when to shift to reproductive development. First, the Arabidopsis gene encoding TERMINAL FLOWER2 (TFL2), homologous to HETEROCHROMATIN PROTEIN1, was isolated and characterised. Mutations in TFL2 result in plants that are dwarfed, flowers early, have reduced sensitivity to day length and terminate the inflorescence in an apical flower. As homologues from other organisms TFL2 is active in gene regulation by gene repression. I show that the gene affect flowering time by the autonomous and the photoperiod pathways, two of four floral inductive pathways. TFL2 act to repress the activity of genes that are promoters of floral meristem identity and interacts genetically with factors known to alter the chromatin state. Further tfl2 is shown to have altered levels of and response to auxin. All together this shows that TFL2 is active as a regulator of several different processes during plant development. Second, I have characterised and studied the function of three genes encoding APETALA2 LIKE proteins in Norway spruce (Picea abies). In spruce these genes are expressed in meristems and reproductive tissues. When constitutively expressed in Arabidopsis two of the genes delays flowering time and alter the function of shoot apical and floral meristems. Together this suggests a function similar to the Arabidopsis homologues.

Norway spruce (Picea abies L. Karst) is a conifer belonging to the group gymnosperms and is an ecologically and economically important species in several parts of Europe. It is crucial for trees like Norway spruce to adapt timing of events such as bud set and growth cessation to the local environment in order to maximize the growth period while avoiding frost damage. This thesis aims at widening the knowledge about genetic control of annual growth rhythm in Norway spruce and particularly the control of bud set. Using spruce transformants ectopically expressing PaFT/TFL1-LIKE 2 (PaFTL2) the prior hypothesis that PaFTL2 induces bud set is confirmed. This is further supported by spatial and temporal expression patterns in seedlings and adult trees. It is further shown that gymnosperms possess at least two FLOWERING LOCUS T/TERMINAL FLOWER 1 (FT/TFL1)-like genes with TFL1-like function, suggesting the ancestor of FT and TFL1 to be more TFL1-like. PaFTL1 appears to have complementary expression patterns to that of PaFTL2 both spatially and temporally indicating they may act together to control growth in Norway spruce. Since bud set is controlled by photoperiod and circadian clock genes are implicated in this process, putative clock homologs were studied to gain insight into the circadian clock in gymnosperms. Several clock homologs were identified and their expression showed a diurnal pattern but the expression was rapidly damped in constant conditions. Transgenic Arabidopsis expressing putative core clock genes from spruce indicate that at least three genes, PaCCA1, PaGI and PaZTL, appear to have a conserved function between angiosperms and gymnosperms. Taken together these results suggest that gymnosperms have a similar core clock structure as angiosperms even though fundamental differences might exist since the cycling of the clock genes were rapidly damped in free-running conditions. The studies presented in this thesis support substantial conservation of pathway components controlling photoperiodic responses in angiosperms and gymnosperms and identify PaFTL2 as a component of growth rhythm control. However, important changes in these processes are also evident. The results provide a solid basis for future research on molecular mechanisms controlling an adaptive trait in an important non-model organism.

Diss. (sammanfattning) Alnarp : Sveriges lantbruksuniversitet, 2009. / Härtill 5 uppsatser.