European aspen and hybrid aspen under changing environment : Leaf traits, growth and litter decomposition

Understanding the responses of species and ecosystems to human-induced global environmental change has become a high research priority. The main aim of this thesis was to investigate how certain environmental factors that relate to global change affect European aspen (Populus tremula), a keystone species in boreal forests, and hybrid aspen (P. tremula × P. tremuloides), cultivated in commercial plantations. The main points under consideration were the acclimatization potential of aspen through changes in leaf morphology, as well as effects on growth, leaf litter chemistry and decomposition. The thesis is based on two experiments, in which young aspen (< 1 year) were exposed either to an atmospheric pollutant [elevated ozone (O3)] or variable resource availability [water, nitrogen (N)]; and two field studies, in which mature trees (> 8 years) were growing in environments exposed to multiple environmental stress factors (roadside and urban environments). The field studies included litter decomposition experiments. The results show that young aspen, especially the native European aspen, was sensitive to O3 in terms of visible leaf injuries. Elevated O3 resulted in reduced biomass allocation to roots and accelerated leaf senescence, suggesting negative effects on growth in the long term. Water and N availability modified the frost hardening of young aspen: High N supply, especially when combined with drought, postponed the development of frost hardiness, which in turn may predispose trees to early autumn frosts. This effect was more pronounced in European aspen. The field studies showed that mature aspen acclimatized to roadside and urban environments by producing more xeromorphic leaves. Leaf morphology was also observed to vary in response to interannual climatic variation, which further indicates the ability of aspen for phenotypic plasticity. Intraspecific variation was found in several of the traits measured, although intraspecific differences in response to the abiotic factors examined were generally small throughout the studies. However, some differences between clones were found in sensitivity to O3 and the roadside environment. Aspen leaf litter decomposition was retarded in the roadside environment, but only initially. By contrast, decomposition was found to be faster in the urban than the rural environment throughout the study. The higher quality of urban litter (higher in N, lower in lignin and phenolics), as well as higher temperature, N deposition and humus pH at the urban site were factors likely to promote decay. The phenotypic plasticity combined with intraspecific variation found in the studies imply that aspen has potential for withstanding environmental changes, although some global change factors, such as rising O3 levels, may adversely affect its performance. The results also suggest that the multiple environmental changes taking place in urban areas which correspond closely with the main drivers of global change can modify ecosystem functioning by promoting litter decomposition, mediated partly by alterations in leaf litter quality.

Hyvän hallinnon muunnelmat : Julkisoikeudellinen tutkimus

This doctoral thesis analyses the concepts of good governance and good administration. The hypothesis is that the concepts are radically indeterminate and over-inclusive. In the study the mechanisms of this indeterminacy are examined: why are the concepts indeterminate; how does the indeterminacy work and, indeed, is it by any means plausible to try to define the concepts in a closed way? Therefore, the study focuses on various current perspectives, from which the concepts of good governance and good administration are relevant and what kind of discursive contents they may include. The approach is both legal (a right to good administration) and one of moral philosophy and discourse analysis. It appears that under the meta-discourse of good governance and good administration there are different sub-discourses: at least a legal sub-discourse, a moral/ethical sub-discourse and sub-discourses concerning economic effectiveness and the promotion of societal and economic development. The main claim is that the various sub-discourses do not necessarily identify each other s value premises and conceptual underpinnings: for which value could the attribute good be substituted in different discourses (for example, good as legal, good as ethical and so on)? The underlying presumption is, of course, that values are ultimately subjective and incommensurable. One possible way of trying to resolve the dynamics of possible discourse collisions is to employ the systems theory approach. Can the different discourses be interpreted as autopoietic systems, which create and change themselves according to their own criteria and are formed around a binary code? Can the different discourses be reconciled or are they indifferent or hostile towards each other? Is there a hegemonic super discourse or is the construction of a correct meaning purely contextual? The questions come back to the notions of administration and governance themselves the terms the good in its polymorphic ways is attempting to define. Do they engage different political rationalities? It can be suggested that administration is labelled by instrumental reason, governance by teleological reason. In the final analysis, the most crucial factor is that of power. It is about a Schmittian battle of concepts; how meanings are constructed in the interplay between conceptual ambiguity and social power. Thus, the study deals with administrative law, legal theory and the limits of law from the perspective of revealing critique.

Physical properties of a boreal clay soil under differently managed perennial vegetation

The physical properties of surface soil horizons, essentially pore size, shape, continuity and affinity for water, regulate water entry into the soil. These properties are prone to changes caused by natural forces and human activity. The hydraulic properties of the surface soil greatly impact the generation of surface runoff and accompanied erosion, the major concern of agricultural water protection. The general target of this thesis was to improve our understanding of the structural and hydraulic properties of boreal clay soils. Physical properties of a clayey surface soil (0 - 10 cm, clay content 51%), with a micaceous/illitic mineralogy subjected to three different management practices of perennial vegetation, were studied. The study sites were vegetated buffer zones located side by side in SW Finland: 1) natural vegetation with no management, 2) harvested once a year, and 3) grazed by cattle. The soil structure, hydraulic properties, shrinkage properties and soil water repellency were determined at all sites. Two distinct flow domains were evident. The surface soil was characterized by subangular blocky, angular blocky and platy aggregates. Hence, large, partially accommodated, irregular elongated pores dominated the macropore domain at all sites. The intra-aggregate pore system was mostly comprised of pores smaller than 30 μm, which are responsible for water storage. Macropores at the grazed site, compacted by hoof pressure, were horizontally oriented and pore connectivity was poorest, which decreased water and air flux compared with other sites. Drying of the soil greatly altered its structure. The decrease in soil volume between wet and dry soil was 7 - 10%, most of which occurred in the moisture range of field conditions. Structural changes, including irreversible collapse of interaggregate pores, began at matric potentials around -6 kPa indicating, instability of soil structure against increasing hydraulic stress. Water saturation and several freezethaw cycles between autumn and spring likely weakened the soil structure. Soil water repellency was observed at all sites at the time of sampling and when soil was dryer than about 40 vol.%. (matric potential < -6 kPa). Therefore, water repellency contributes to water flow over a wide moisture range. Water repellency was also observed in soils with low organic carbon content (< 2%), which suggests that this phenomenon is common in agricultural soils of Finland due to their relatively high organic carbon content. Aggregate-related pedofeatures of dense infillings described as clay intrusions were found at all sites. The formation of these intrusions was attributed to clay dispersion and/or translocation during spring thaw and drying of the suspension in situ. These processes generate very new aggregates whose physical properties are most probably different from those of the bulk soil aggregates. Formation of the clay infillings suggested that prolonged wetness in autumn and spring impairs soil structure due to clay dispersion, while on the other hand it contributes to the pedogenesis of the soil. The results emphasize the dynamic nature of the physical properties of clay soils, essentially driven by their moisture state. In a dry soil, fast preferential flow is favoured by abundant macropores including shrinkage cracks and is further enhanced by water repellency. Increase in soil moisture reduces water repellency, and swelling of accommodated pores lowers the saturated hydraulic conductivity. Moisture- and temperature-related processes significantly alter soil structure over a time span of 1 yr. Thus, the pore characteristics as well as the hydraulic properties of soil are time-dependent.

Vänner, kolleger och gynnare : Namngivningen av de finska fästningsverken under Augustin Ehrensvärds tid

Under 1700-talets andra hälft hörde Sveriges nya fästningar i öst (Helsingfors, Sveaborg, Lovisa och Svartholm) till rikets största satsningar. Fästningsprojektet leddes med undantag av ett par avbrott av Augustin Ehrensvärd (1710 1772). När arbetet tog fart namngavs de enskilda fästningsverken i så gott som alla fall efter samtida personer. Under Ehrensvärds tid tillämpades denna namngivning på omkring femtio av Sveaborgs och Helsingfors fästningsverk samt på Lovisas och Svartholms totalt aderton verk. Genom personerna de knöts till berättar namnen en hel del om Augustin Ehrensvärds samtid och omvärld. Hur de gjorde det är denna avhandlings huvudfråga. Källmaterialet utgörs av relationsritningar och brev, medan de teoretiska ramarna står att finna i nätverksteori och onomastiska teorier om namnmönster. Ehrensvärd förklarade sin namngivningspraxis för sin överordnade, tronföljaren Adolf Fredrik, 1749 i samband med att Gustavssvärd med fästningsverk namngavs: tanken var att namnge bastioner efter de som bidragit till arbetets framgång och att namnge utanverk efter officerare vid fästningsbygget. Innebörden av Ehrensvärds ord framgår ur namnbeståndet. De största grupperna består av ämbetsmän och militärer. Med de som bidragit till arbetets framgång avsågs sålunda den lokala eliten: landshövdingar som involverats i fästningsbygget samt högre och lägre militärer som tjänstgjorde vid fästningarna. Redan från början syns en klar hierarki i namngivningen. Medan landshövdingarna och de högre militärerna tillägnades bastioner, fick de lägre officerarna se mindre fästningsverk namngivna efter sig, helt i enlighet med Ehrensvärds egen beskrivning. Utanför de ovan nämnda grupperna, hedrades en hel del personer som inte konkret hade engagerats i fästningsbygget. Denna namngivning kan förklaras å ena sidan inom ramen för Ehrensvärds sociala nätverk och å andra sidan mot bakgrund av riksdagspolitiken i frihetstidens Sverige. Av de två förklaringsmodeller bör Ehrensvärds personliga vänskaper ses som en bidragande orsak, medan de politiska motiven utgjorde en avgörande orsak. Som en del av Ehrensvärds nätverk kan de gynnare ses som hade stöttat Ehrensvärd under hans karriär samt hans närmaste medarbetare vid fästningsbygget, ofta officerer han själv handplockat. Namngivningens politiska aspekt syns i det stora antalet riksråd som tillägandes bastionnamn. Vid sidan om riksråden hedrades också talmän vid de samtida riksdagarna. En komparativ studie i namngivningen av fästningsverk vid samtida och äldre svenska fästningar framhäver Ehrensvärd som en innovativ namngivare. Fästningsverk namngivna efter kungligheter verkar ha varit en norm, som också Ehrensvärd anknöt till genom ett fåtal namn. Däremot var namn efter personer inte vanliga, vilket gav den Ehrensvärdska namngivningen en förhållandevis stark anknytning till samtiden. Denna aspekt bekräftas om namnen ses mot bakgrund av 1700-talets uppfattning om ära och äregirighetens samhälleliga nytta. I denna uppfattning syns bakgrunden till förekomsten av personer med både hög och låg status i Ehrensvärds namngivning. Sammanfattningsvis speglar namnen på de finska fästningsverken sin samtid genom den byråkratiska, militära och politiska elit de representerar samt genom motiveringen till dem.