Nitrogen transformations in boreal forest soils in response to extreme manipulation treatments

providing me these excellent working facilities and the support of Metla. I want to thank my supervisor Docent Aino Smolander for her endless support and encouragement. As for the past few years I was engaged with an another project, I think I could not have completed this work without having such a good supervisor! I also value the fun field trips we shared. To the "extended soil group" I am grateful for the friendly atmosphere and for all the help. Doctors Taina and Outi – my idols in the process of becoming one myself-I consider myself extremely lucky for having friends like you. you for the great moments we have shared both in and out of work. Special thanks to Tuula for constructive comments on my texts and Hannu for organizing those fun boat trips. Veikko, I really appreciate your skills in analytical chemistry, without you there would be no terpenes in this work. Thank you to Pirkko and Hillevi for taking care of the paperwork, Anne, Leena and Sari for drawing excellent figures (and for not getting annoyed with me continuously changing them), Marja for help in statistics and Maarit M. for help in the laboratory. I also appreciate very much the help from the people in Keskuslaboratorio, especially the numerous FIA measurements done by Marja-Leena and Pirkko H. Aino for the very fruitful cooperation. My special thanks to Heljä-Sisko for skillfully coordinating this project and for the nice field trips, to Antti-Jussi for constant help with problems related to deposition and leaching and to Joonas for revising the language of this thesis. Warm thanks to Heikki Heino and Leo Aspholm from the Hämeenlinna Waterworks and Risto Reijonen from the Finnish Groundwater Techniques for the possibility to conduct research on Ahvenisto esker infiltration site and for the pleasant cooperation. I also appreciate very much the help in the fieldwork by the personnel of the Hämeenlinna Waterworks. The "ViVa"-project was funded by the Waterworks of the cities of Hämeenlinna, Jyväskylä, Mikkeli, the Tampere-Valkeakoski area, the Turku area and the Tuusula area, which are all acknowledged. and Tuula for the helpful atmosphere and for the coffee breaks full of laughter. My special thanks to my new supervisor Jarkko Hantula – you must be one of the most understanding person on earth. I also have very fond memories of the adventure in Scotland with Eeva, Jarkko and Michael. I want to thank …