Abstract The study focused on geological and ecological development of ten lacustrine basins in the Hailuoto – Oulunsalo – Lumijoki siltstone and claystone area of Muhos, and two lacustrine basins in the Kuivaniemi – Simo area of Svecokarelian schists and gneisses. The study on water quality, soil and sediment geochemistry, and sediment diatom assemblages of natural lacustrine basins, provide background values, which can be used in assessing the state of the water body in environmental studies. Water quality of the ten water bodies was monitored for 14 years. Water samples were studied for 28 different parameters. Soil and sediment geochemistry was studied on seven lacustrine basins by three different extraction methods. Extracts were analysed for ten parameters. The sediment diatom species were examined from five water bodies in accuracy of 1 cm thick layers. In the study area new water bodies are forming mainly in two different ways: isolation of marine bights and damming of dune ponds. The water bodies could be classified into five different groups based on water quality, sediment geochemistry, and sediment diatom assemblages. These also represent the different developmental stages of the lacustrine basins of the land uplift coast. Parameters of the water quality data could be divided into two main groups: electrolyte group and nutrient group. The water bodies studied segregated into two main categories: coastal and inland water bodies. The concentrations of electrolytes and nutrients were characteristically higher in the coastal water bodies compared to the inland water bodies. During the monitoring period eutrophication of the water bodies and significant seasonal variations of water quality were observed. According to the water quality data and diatom indices the prevailing conditions in the coastal water bodies were eutrophic; and in the inland water bodies ranging from mesotrophic to oligotrophic. The lacustrine basins were grouped mainly in accordance with their geochemical provinces. The geochemical gradients of soil, water quality and sediment in the chronosequence of the catchments on Hailuoto Island showed that when marine influence decreased, the lacustrine basins of the land uplift coast were observed to be oligotrophying, acidifying, and terrestrializating naturally. / Tiivistelmä Tutkimus keskittyi kymmenen Hailuodon, Oulunsalon, ja Lumijoen Muhos-muodostuman hiekka- ja savikivialueen järvialtaan sekä kahden Iin ja Simon svekokarelisen liuske- ja gneissialueen järvialtaan geologisen ja ekologisen kehityksen selvittämiseen. Luonnonmukaisesti kehittyneen järviallassarjan veden laadun, maaperän ja sedimentin geokemian sekä sedimentin piileväkoostumuksen tutkimus tarjoaa tausta-arvoja, joita voidaan hyödyntää arvioitaessa vesialueen tilaa ympäristötutkimuksissa. Kymmenen vesialtaan veden laatua seurattiin 14 vuoden ajan. Vesinäytteistä analysoitiin 28 eri parametria. Seitsemän järvialtaan valuma-alueen maaperän ja sedimentin geokemiaa tutkittiin käyttäen kolmea erilaista uutosmenetelmää. Uutoksista analysoitiin 10 parametria. Viiden vesialtaan sedimentin piilevälajisto tutkittiin 1 cm:n kerrostarkkuudella. Tutkimusalueella uusia vesialtaita muodostuu pääasiassa kahdella tavalla: merenlahdekkeiden kuroutumisen ja dyynilampien patoutumisen seurauksena. Vesialtaat voitiin luokitella veden laadun, sedimentin geokemian ja piilevälajiston perusteella viiteen eri ryhmään, jotka edustivat myös maankohoamisrannikon järvialtaiden eri kehitystasoja. Vedenlaatuaineiston parametrit voitiin jakaa kahteen pääryhmään: elektrolyyttiryhmä ja ravinneryhmä. Tutkittavat altaat erottuivat kahteen pääluokkaan: ranta-altaat ja sisämaan altaat. Tunnusomaista ranta-altaille verrattuna sisämaan altaisiin oli korkeammat elektrolyyttien ja ravinteiden pitoisuudet. Seurantajaksolla havaittiin ranta-altaiden luontaista rehevöitymistä sekä merkitseviä veden laadun vuodenaikakohtaisia vaihteluita. Vedenlaatuaineiston ja piileväindeksien mukaan vallitsevat olosuhteet rannan vesialtaissa olivat eutrofiset ja sisämaan vesialtaissa mesotrofisista oligotrofisiin. Järvialtaat ryhmittyivät lähinnä geokemiallisten provinssiensa mukaisesti. Hailuodon valuma-alueiden maaperän, veden laadun ja sedimentin geokemialliset gradientit osoittivat, että merellisen vaikutuksen vähetessä maankohoamisrannikon järvialtaat luontaisesti karuuntuvat, happamoituvat ja soistuvat.

The aim of this thesis is to present and examine the names of the islands in the archipelago of Luleå innorthern Sweden. The basis for the studies is a collection of names, which contains written forms excerpted fromsources from the 14th to the 20th century and local pronunciations of old as well as modern names. The names ofthe islands in the collection have been studied from three aspects.The first study (chapter 2) deals with the structure of the names and especially that of names of islands in doublecompound. The lack of s in names like Storhäll-gründet, where dialects in the south of S weden and StandardSwedish would have Storhälls gründet, is the starting point of the investigation. (Some double compounds have sin the compounding link like Bullerskärs-grundet. They are also discussed.)The hypothesis advanced is that the dialectal distribution of the accent in the names in northern Sweden makes itpossible to show where the link in the double compound is, so the 5, which in Standard Swedish and in thedialects in the south of Sweden is needed to mark the semantic limit between the parts of the compound, is notneeded in the dialects of northern Sweden.The stress in double compounds of th e type AB-C (see above) is on the last element of the name or word: -——. Names in double compound of the type A-BC like Lill-Kvarnören have a different type of accent: — — 1with the stress on the first element of the name or word. The two different main accents in double compounds ofthe type AB-C and A-BC: J— — and — —1 have the status of markers showing where the compounding link inthe compound is, so the s is not needed in the compounds of the type AB-C in the dialects of northern Sweden.The study includes names of isl ands containing double compounds in the whole of Norrbotten and appellativedouble compounds from a collection of words from a village in Nederluleå.The second study (chapter 3) deals with the relationship between the names and the land uplift. The BothnianBay is an area of rapid land uplift. The land uplift has its highest estimated values, 0,9 meters in 100 years, on thecoast north of Skellefteå up to Luleå. Many names of islands have disappeared because the islands have beenuplifted, especially in what used to be large bays, now large shallow lakes like Persöfjärden. New water-surroundedareas have on the other hand been named like Sandgrönnorna, described from old maps from 1790 and fromphotographs from 1946.Chapter 3 consists of three sections, in which separate studies of names in relation to the land uplift are presented.The first section deals with the names ending in -gründet, -grunden. Originally names of under-water localities,they are now names of small islands and gründet has changed its denotation to 'small island' in the area.The second section in chapter 3 presents a method for the dating of names of island in uplifted areas. Many largeislands, now uplifted, still have the names they had as water-surrounded islands. By following the equidistancecurves around the locality it is possible to find out at what equidistance it was surrounded by water. Before thattime it must have been named as an island. That is terminus ante quem, TAO, for the name. The third sectiondeals with the names of vattung, which can be dated from the time of th eir rise above the sea level. A vattung, 5meters high, can thus be about 500 years old, terminus post quem, TPQ, about 1450. The studies presentedabove show that some names can be dated to the Viking Age.The third study (chapter 4) deals with the names of large islands and the colonization. The colonization period ofthe northern part of Sweden is reflected in many names of large islands containing personal names like Hertsönand Germandön. No archipelago in Scandinavia shows such an amount of names of islands containing personalnames. Most personal names are Nordic and can be compared to those in the names ending in -mark in Västerbottenand the south of Norrbotten. - Some of t he names of islands containing personal names have also beendated in chapter 3. They are among the oldest names in Nederluleå.In chapter 5 the names in the studies are put in relation to the historical and archaeological records in Norrbottenand can thus contribute to throwing light upon the colonization period of northern Sweden. / digitalisering@umu

Semi-natural grasslands with traditional management are known to be very species-rich, with many plant species strongly associated with the habitat. The last century’s decline of semi-natural grasslands, as a result of land use change and abandonment, has made the remaining semi-natural grassland a high concern for conservation. Since management can be costly and the available resources often are limited, it is important to use the most beneficial management method for preserving and enhancing the biodiversity. One semi-natural grassland type of certain interest around the Baltic region are coastal grasslands. In this study, I investigated vascular plant species occurrence in ten managed coastal grasslands located in the Stockholm archipelago. The effect of recent land-uplift and future sea level rise on the ten coastal grasslands were analyzed as well. A major part of all ten grasslands had been subjected to the process of isostatic land-uplift the past 100 years. Five of the grasslands were currently managed by grazing and the other five were managed by traditional mowing. There was no significant difference in alpha and gamma diversity between the two management types. Though, higher biodiversity values, such as more different species found in total, higher amount of species typically linked to meadows and pastures, less succession species and more red-listed species, were found in the traditionally mowed grasslands. Furthermore, a sea level rise with 40 cm the next 100 years in the region would lead to loss of plant species diversity in the investigated coastal grasslands. One major concern is the limited areas upwards on the coastal grasslands for species to migrate to in the future, which is expected to primarily affect species associated with meadows and pastures. The study highlights the importance of open and managed grassland areas further up the coastal grasslands for local species to migrate to, if the sea level would rise as predicted by future climate scenarios. Albeit weak the results of this study indicate that traditional mowing generates higher biodiversity values compared to grazing, hence it should be the preferred management method in coastal grasslands in the Stockholm archipelago.

Abstract Succession is a compositional change of species and other ecosystem characteristics over time. Mire development, i.e., long-term mire succession is basically driven by an increase in peat layer height, promoting changes in hydrology, vegetation and nutrient status of a particular mire. Due to this, ecosystem processes, such as production and loss of carbon due to decomposition (i.e. carbon gas functions), change with increasing successional mire stage. An adequate method for studying the changes in ecosystem C functions is to measure CO2 and CH4 fluxes between the ecosystem and atmosphere. Succession and carbon dynamics of boreal pristine mires have been much studied. However the link between these phenomena is largely unknown. Further, if and how the C gas functions of mires change during mire succession it is rather poorly understood. The main objective of this thesis was to study how ecosystem functions, measured as CO2 and CH4 exchange, change during mire development. The study also aims to explore the drivers of succession in mire development, i.e., mire succession. Successional mire C dynamics were studied along an eight-kilometer-long successional sequence of primary paludified mires located in the land uplift coast of the Bothnian Bay. Due to the short distance between sites, they all have been under the same climatic control for most of their development. The gradual replacement of plant species with different photosynthetic potential, phenology and assimilating green area resulted in lower-level and temporal variation of CO2 exchange patterns at the later successional stages. Similar to this, CH4 also had the lowest interannual variation in the later stages. In general, CH4 emissions increased with mire age even though this trend did not emerge during the rainy season. Further, this study showed that the wintertime C function pattern was related to the C pattern during the previous summer confirming the important effect of growing season patterns on wintertime C dynamics. In addition to the fundamental effect of vegetation as a driver of succession which was also confirmed in this study, the role of hydrological conditions appeared to be equally important. More constant hydrological conditions at later successional stages resulted in lower temporal variation in CH4 and CO2 fluxes. The present results suggest that the stability of ecosystem C gas functions increases during mire development due to increasing autogenic control. / Tiivistelmä Sukkessio on ekosysteemin lajistossa ja sen muissa ominaisuuksissa ajan kuluessa tapahtuva muutos. Suon kehitystä eli pitkäaikaista suosukkessiota vie eteenpäin turpeen paksuuskasvu, joka saa aikaan muutoksia suoekosysteemin hydrologiassa, kasvillisuudessa ja ravinnetilassa. Tästä johtuen myös suoekosysteemin erilaiset prosessit, kuten tuotanto sekä hajoamisen kautta tapahtuva hiilen vapautuminen eli hiilikaasutoiminta muuttuu suon ikääntyessä. Ekosysteemin hiilikaasutoiminnassa tapahtuvia muutoksia voidaan tutkia muun muassa mittaamalla ekosysteemin ja ilmakehän välisiä hiilidioksidi- ja metaanivirtoja. Boreaalisten luonnontilaisten soiden sukkessiota ja hiilidynamiikkaa on tutkittu runsaasti, mutta niiden välistä yhteyttä ei sen sijaan juuri tunneta. Tämän vuoksi ei tiedetä kuinka soiden hiilikaasutoiminta mahdollisesti muuttuu suon kehityksen aikana eli suosukkession edetessä. Tämän tutkimuksen päätavoitteena oli tutkia kuinka hiilidioksidin ja metaanin vaihdolla mitattu ekosysteemitoiminta muuttuu suon kehityksen aikana. Tutkimus pyrki myös selvittämään suosukkessiota kontrolloivat tekijät. Eri-ikäisten soiden hiilikaasudynamiikkaa tutkittiin mittaamalla hiilikaasuja Perämeren maankohoamisrannikolla kahdeksan kilometrin pituisella sukkessiogradientilla, joka koostuu primaarisoistumisen kautta syntyneistä soista. Soiden lyhyestä keskinäisestä etäisyydestä johtuen ne ovat olleet saman ilmastollisen kontrollin alaisena suurimman osan kehityksestään. Vaiheittainen kasvilajien muutos sukkessiogradientilla yhdessä kasvilajien erilaisen yhteyttämispotentiaalin, fenologian ja yhteyttävän lehtipinta-alan kanssa johti hiilidioksidivaihdon alhaisempaan tasoon sekä pienempään ajalliseen vaihteluun vanhemmilla sukkessiovaiheilla. Myös metaanin vaihdolla oli alhaisimmat vuosien väliset vaihtelut vanhemmilla vaiheilla. Yleisesti ottaen metaanipäästöt kasvoivat suon iän myötä, vaikkakaan tätä trendiä ei havaittu sateisena kasvukautena. Lisäksi tutkimus osoitti, että talviaikaiset hiilivirrat (CO2, CH4) seurasivat kesäaikaisen hiilidynamiikan vaihtelua. Kasvillisuuden keskeinen rooli ekosysteemin sukkessiossa havaittiin myös tässä tutkimuksessa. Kasvillisuuden ohella merkittäväksi suosukkessiota sääteleväksi tekijäksi osoittautui hydrologisten olojen vaikutus. Tasaisemmat hydrologiset olot vanhemmilla sukkessiovaiheilla johtivat vähäisempään ajalliseen vaihteluun metaani- ja hiilidioksidivirroissa. Tutkimuksen tulokset viittaavat siihen, että ekosysteemin hiilidynamiikka stabilisoituu suon kehityksen aikana lisääntyvän autogeenisen kontrollin kautta.