Browsing by Subject "suokasvillisuus"

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  • Lindholm, Tapio; Heikkilä, Raimo (Finnish Environment Institute, 2006)
    The Finnish Environment 23/2006
    Finland - Land of mires is a textbook on mires and their ecology in Finland. Totally 27 separate articles of different topics are included in the book. The items dealt with in the book are the following: 1. Unsettled weather and climate of Finland. 2. Climate of Finland and its effect on mires. 3. Bedrock in Finland and its infl uence on vegetation. 4. The landforms of Finland. 5. Glacial and postglacial history of the Baltic Sea and Finland. 6. Postglacial history of Finnish inland waters. 7. Lake and river systems in Finland. 8. Interglacial and interstadial organic deposits in Finland. 9. Mire development history in Finland. 10. Regional distribution of peat increment in Finland. 11. Geobotany of Finnish forests and mires: the Finnish approach. 12. Ecohydrology of Finnish mires. 13. Ecological gradients as the basis of Finnish mire site types. 14. Mire plant species and their ecology in Finland. 15. Land uplift phenomenon and its effects on mire vegetation. 16. Palsa mires in Finland. 17. Cultural land use history in Finland. 18. The use of mires for agriculture and forestry. 19. Destruction of mires in Finland. 20. Environmental impacts of mire utilization. 21. Peatlands and global change - the Finnish case. 22. Ecosystem services provided by Finnish mires. 23. Mire conservation and its short history in Finland. 24. Ramsar areas in Finland. 25. Land birds in Finnish mires and their conservation status. 26. A short introduction to the Finnish language. 27. Etymology of some Finnish words for mire.
  • Brandt, Alfred (Suomen metsätieteellinen seura, 1933)
  • Juselius, Teemu (Helsingfors universitet, 2017)
    Nowadays a greater number of people live in cities than in earlier times. In Finland, the portion of urban dwellers has nearly doubled in last 50 years. The urbanization has had undisputable benefits for mankind but it has also had widespread negative effects on nature. As cities grow natural habitats are replaced by spreading infrastructure. Remaining mires, forests and other natural habitats are smaller and more isolated than their rural counterparts. These urban habitats are affected by increased pollution and nutrient loads, trampling and other detrimental effects caused by human activity. Alien invasive species may also spread into indigenous vegetation and more of these areas are affected by edge-effects. Ombrotrophic bogs are one of the most nutrient-poor habitats in the North and receive nutrients only by dry and wet deposition. They have been reported to suffer from increased nutrient deposition. Hydrology also has a vital part in function and form of ombrotrophic bogs. Spread of urban infrastructure may alter the way bogs receive water due to increased sealed surface in the catchment areas of these bogs. The effects of urbanization on ombrotrophic bogs in Finland has not been studied previously and the aim of this Master’s thesis is to examine the differences between vegetation in urban and rural bogs and the effects of the size of bog area, nearby population and total N content of surface peat on bog vegetation in different bog types: dwarf shrub pine bogs, low sedge bogs, Sphagnum fuscum pine bog and Sphagnum fuscum bog. Last two were studied together due to their similarities. According to this study the differences between urban and rural bogs in Southern Finland are small. The greatest differences were observed among dwarf shrubs typical for bogs but the effects varied between bog types. In dwarf shrub pine bogs, the amount of dwarf shrubs decreased while in low sedge bogs, the cover of Vaccinium oxyccocos, and in Sphagnum bogs, the occurrence of Empetrum nigrum increased. The bogs studied in urban sites were generally smaller and more isolated than rural bogs. Around urban bogs, there were also significantly higher number of residents than in rural areas, and one of the most distinct effects of urbanization on bog vegetation discovered was reduction of cover and appearance of species vulnerable to trampling. The increased nutrient loads usually reported in urban habitats was not visible in nitrogen content of surface peat. On the contrary, low sedge bogs seemed to have higher nitrogen content on rural bogs, which may be caused by intense agriculture in rural areas. The reason for not detecting increased urban nitrogen deposition based on peat samples may be caused by increased nitrogen uptake of Sphagnum mosses. Sphagnum mosses have been reported to benefit from increased nitrogen deposition until they reach nitrogen saturation point. After this the excess nitrogen enters peat soil. Low nitrogen deposits in Southern Finland can probably be used fully by Spaghnum mosses and thus no increase in nitrogen content was observed. The results of this study indicate that ombrotrophic peat bogs are at least partly resistant to the effects of urbanization. The level of urbanization in Finland is lower than in Central Europe, which may lead to lowered levels of detrimental effects caused by urbanization. Alien species are probably also unable to invade the acidic and nutrient poor urban bogs. The mire types studied here are also usually situated in the centre of ombrotrophic bogs and may have avoided most of the edge effects. However, if studied, the edges of the urban bogs might have shown large number of harmful effects caused by urbanization.
  • Ruuhijärvi, Rauno; Kukko-Oja, Kari (Vesihallitus, 1975)
    Vesihallitus. Tiedotus 87
    Nature in the Kemihaara reservoir area, Northern Finland.
  • Elina, Galina A.; Lukashov, Anatoly D.; Yurkovskaya, Tatyana K. (Finnish Environment Institute, 2010)
    The Finnish Environment 4/2010
    The monograph is a generalization based on the analysis and synthesis of the voluminous scope of data on the dynamics of palaeovegetation and its mapping, along with aspects of palaeogeography of the Kola Peninsula and Karelia. All the elements of past landscapes are considered against the background of the present state of environments: geology, geomorphology and vegetation. The interval under consideration embraces the Late Glacial Time (12 000-10 300 years BP) and the Holocene (from 10 300 years BP up to the present). The book discusses the methodical and theoretical treatments of the last decade. As a result, the dynamics of past landscapes are shown in the unity of all their components (i.e., relief, hydrology and vegetation), and in comparison with their present-day parameters. Cartographic and textual materials on geology and modern vegetation as well as palaeovegetation maps of model territories used in this book are entirely original. The model territories are rather evenly distributed throughout the Kola Peninsula and Karelia. Seven of them are represented in this work; for each of model territory, a series of maps (for 10 500, 9 500, 8 500, 5 500, 3 000, and 1 000 years BP) are provided, correlated with relief and present-day vegetation. The second stage of data generalization is a comparison of maps related to the same temporal sections. The sequence of the maps from ‘older’ to ‘younger’ characterizes the dynamics of chorological palaeovegetation units. These dynamics readily illustrate shifts of geographical zones in space and time.
  • Sormunen, Janne (Helsingin yliopisto, 2014)
    Boreal peatlands are diverse ecosystems and globally significant carbon sinks. Changes in environmental conditions might alter their vegetation and the amount of carbon fixation. The amount and composition of peatland vegetation is determined by air and peat temperature and hydrology. The air temperature is expected to rise on average by 1,2 – 4,8 °C, increasing the amount of droughts and lowering the water table level of fens by 8 – 14 cm. Fens may be especially vulnerable to changes in environmental conditions because they receive most of their nutrient input through groundwater flow and run-off. The aim of the research was to study the effect of warming and drying on the leaf area, phenology, leaf biomass production and composition of the plant community. The study site was an oligo-mesotrophic fen situated in central Finland. Vegetation was monitored throughout the growing season. The site was divided into a ditched area where the water table was lowered on average by 8 cm and to a pristine area where the water table remained at its natural state. Vegetation monitoring plots were warmed with plastic open top chambers. The walls were tilted inward in order to trap solar radiation inside the chamber, warming the air temperature on average by 2,3 °C. The results indicated that climate warming will affect the vegetation mostly through water level drawdown. Water table drawdown had no effect on the leaf biomass production of the whole plant community but it changed its composition. The amount of sedges remained unchanged and they continued to be the dominant plant group. Lowering of the water table increased the amount of evergeen shrubs and promoted the emergence of decidious shrubs. The amount of herbs dropped significantly because they require a more moist environment. Warming had no effect on leaf biomass production or species composition but it increased the development rate of leaf area until peak leaf area was reached. Water level drawdown on the other hand slowed down the development rate of leaf area. Together warming and water table drawdown increased the length of the growing season of sedges and the whole community. The ecosystem seems to adapt to changing environmental conditions through changes in the plant community composition, leaving the amount of leaf biomass production and carbon fixation unchanged despite the changes. The decrease of the more nutrient dependent species and the increase of species accustomed to more nutrient poor habitats might imply the beginning of gradual ombrotrophication of fens as the climate changes.
  • Lindholm, Tapio; Heikkilä, Raimo (Finnish Environment Institute, 2012)
    The Finnish Environment 38/2012
    Mires from pole to pole is a proceedings volume of the XII biennial International Mire Conservation Group symposium held in Finland 24.-27.7. 2006. The following topics are included in the volume: 1. Towards the understanding of the variety of mires and their conservation in different countries, 2. Patterns in polygon mires in north-eastern Yakutia, Siberia: The Role of Vegetation and Water, 3. Mires on the map of Russia, 4. Development of the large-scale hydrotopography of aapa mires on the land-uplift coastland in northern Finland, 5. The development of patterning on a succession series of aapa-mire systems on the land-uplift coast of northern Ostrobothnia, Finland, 6. The beginning of agriculture in Swedish Lapland, 7. Moss diversity in the mires of the Maanselkä water divide, 8. Vegetation studies and mapping in Juortanansalo mire reserve, eastern Finland, 9. Holocene vegetation dynamics and carbon accumulation of two mires in the Friendship Park, eastern Finland, 10. Vegetation dynamics of the Ileksa-Vodlozero aapa mires, 11. Vegetation of forested mires in the middle boreal subzone of Karelia, 12. Mire flora, vegetation and conservation in the Republic of Karelia, Russia, 13. Mire types of the southern part of Kenozero National Park, Arkhangelsk region, NW Russia, 14. Postdrainage vegetation dynamics in mesotrophic herb-Sphagnum mires of southern Karelia, Russia, 15. The Finnish peat mining paradox: political support to environmental calamity, 16. Nationally and regionally threatened mire mosses in Finland, 17. Assessment of threatened mire habitats in Finland, 18. Monitoring restored peatlands in Finnish nature reserves, 19. Species richness and abundance of butterflies in natural and drained mires in Finland, 20. Impacts of peatland restoration on nutrient leaching in western and southern Finland, 21. Role of protected areas in maintaining the diversity of peat mosses in the Karelian Isthmus and Gulf of Finland islands (Leningrad Region, northwest Russia), 22. Sphagnum cover surface shape variations during vegetation period, 23. Plant cover of natural mires and disturbed peatlands in Meschera National Park, Russia, 24. Management and monitoring of three Latvian raised bogs and a fen, 25. The Origin, Development, and Modern State of Karst Mires in the Tula Region of Russia, 26. Subsidence in bogs. Moving catchment boundaries, changing flow paths and slopes, self-sealing and effects on drying and natural rewetting, 27. The importance of gradual changes and landscape heterogeneity for aquatic macroinvertebrate diversity in mire restoration management, 28. Mires in Slovakia - present status and conservation, 29. Status and Protection of Heilongjiang Wetlands in North-eastern China, 30. Experimental grazing management on peatlands of the French Basque Land, 31. Hydrogeochemical Investigation of Peatlands and related Vegetation Complexes, 32. The invasive alien plant species of Kolkheti lowland, Georgia, 33. Spatial analysis and description of eastern peatlands of Tierra del Fuego, Argentina, 34. Mires Down Under – the Peatlands of Australasia.
  • Heikkilä, Raimo; Lindholm, Tapio; Tahvanainen, Teemu (Finnish Environment Institute, 2006)
    The Finnish Environment 28/2006
    This book presents a transect of Finnish mire nature from Forest Lapland in the north to the hemiboreal mires on the southern coast of Finland. It has been compiled in connection with the International Mire Conservation Group field symposium in Finland in July 2006, and it gives an overview of the biodiversity of Finnish mires on mire system, massif, site and species levels as well as about the ecology, utilization, conservation and restoration of Finnish mires. A special topic is the primary succession of mires on the land uplift coast of the Bothnian Bay, which is a globally unique phenomenon in the boreal zone. Most of the mires presented here are protected as national parks or mire reserves. Thus this book gives a positive view over Finnish mires. We must remember, however, that about 75 % of Finnish mires have been destroyed by forestry drainage, agriculture, peat mining or reservoir building. The aim of this book is to emphasize the great diversity and high conservation value of Finnish mires. During the compiling of this book it was revealed that despite a long mire research tradition and intensive inventories conducted in nature reserves recently, we know surprisingly little about our mires. This emphasizes the importance of mire research in Finland - land of mires.
  • Helin, Jussi-Pekka (University of Helsinki, 1996)
  • Laitinen, Jarmo; Ojanen, Paavo; Aapala, Kaisu; Hotanen, Juha-Pekka; Kokko, Aira; Punttila, Pekka; Rehell, Sakari; Tiainen, Juha; Vasander, Harri (Suoseura, 2020)
    Suo 71 (2) (2020)
    Suoluonto on hyvin vaihtelevaa, koska suolla vaihtelevat märkyys ja ravinteisuus ja niiden seurauksena myös puustoisuus. Suoluonnon tärkein säätelijä on märkyys – lähellä maanpintaa oleva vedenpinta. Vaikka kaikki suot ovat märkiä, suon märkyys myös vaihtelee paljon. Kuivimmillaan suo muistuttaa kivennäismaan metsää, ja usein suo vaihettuukin saumattomasti ympäröiväksi metsäksi. Märimmillään suo muistuttaa jo matalaa vesistöä ja vaihettuu rantakosteikoihin ja vesistöihin. Suo voi olla ravinteisuudeltaan rehevä tai karu. Rehevässä ääripäässä suolle valuu ravinteikasta vettä ympäristöstä tai kasvillisuus saa ohuen turvekerroksen läpi ravinteita ravinteikkaasta kivennäismaasta. Karussa ääripäässä turvetta on kertynyt niin paksu kerros, että kasvien juuret eivät yllä ottamaan ravinteita alla olevasta kivennäismaasta. Myöskään ympäristöstä ei valu ravinteikasta vettä suon reunaa korkeammaksi kohonneelle suon keskiosalle, ja kasvillisuus on sadeveden mukana tulevien ravinteiden varassa. Lisäksi turpeen kertyminen ja suon läpi virtaavan veden väheneminen happamoittavat turvetta, mikä vaikeuttaa kasvien ravinteiden ottoa. Ravinteisuuden ja märkyyden lisäksi aluskasvillisuuden kasvuoloihin vaikuttaa valon määrä, jota säätelee puuston varjostus. Runsaspuustoisimmat suot ovat varjoisia ja reheviä kuusi- ja lehtipuuvaltaisia korpia tai karumpia mäntyvaltaisia rämeitä. Mitä märempi ja karumpi suo on, sitä vähäisempää puusto on. Märimmät suot ovat ravinteisuudesta riippumatta puuttomia lettoja ja nevoja. Karuimmilla puustoisilla soilla kasvaa niin kitukasvuinen ja harva männikkö, ettei se käytännössä varjosta aluskasvillisuutta. Ojitus vähentää suoluonnon vaihtelua. Kun suo ojitetaan metsätaloutta varten, märkyyden vaihtelu vähenee ja jäljelle jää ravinteisuuden vaihtelu. Tällöin suo alkaa kehittyä aluskasvillisuudeltaan kivennäismaan metsää muistuttavaksi turvekankaaksi. Myös metsänhoito ja hakkuut muuttavat kasvillisuutta. Jos suo raivataan maataloutta varten, kuivatuksen lisäksi suo muokataan viljelyyn sopivaksi kalkituksin ja lannoituksin ja suokasvillisuus raivataan viljelykasvien tieltä. Turpeennostoa varten suo raivataan kasvittomaksi turvekentäksi.
  • Kurki, Kirsi (Helsingfors universitet, 2011)
    Mires have a significant role in climate change mitigation due to their enormous carbon storage and due to the fluxes of greenhouse gases between ecosystem and the atmosphere. Global warming is predicted to affect mire vegetation indirectly through increased evapotranspiration leading to decreased water table levels down to 14–22 centimeters. Water level drawdown is likely to affect the vegetation composition and consequently the ecosystem functioning of mires. Previous studies covering the first years following water table level drawdown have shown that vascular plants benefit from a lower water table and hollow-specific Sphagnum species suffer. In addition to changes in plant abundances the diversity of plant communities decreases. The lawn and hollow communities of Sphagna and sedges are found to be the most sensitive plant groups BACI (before-after-control-impact) experimental approach was applied to study the responses of different functional mire plant groups to water level drawdown. There were 3 control plots and 3 treatment plots with moderate water level drawdown. In addition there were 3 plots drained for forestry 50 years ago as a reference. The plots were located in meso-, oligo- and ombrotrophic sites in Lakkasuo (Orivesi, Finland). The vegetation was surveyed and the water table (WT) was measured from permanent sampling points before ditching in 2000 and during the years 2001–2003 and 2009. The data was analyzed with multivariate methods such as TWINSPAN (PC-Ord), PRC and DCA (CANOCO). Overall results show that the control and treatment plots were similar before the treatment which is crucial in studies conducted with BACI- experimental design. The vegetation composition in the varied between the years also in the control plots following variation in weather conditions, i.e. growing season temperature and precipitation. The year 2003 stood out with lowest water table levels and with highest coverage of the evergreen vascular plants in all plots. By 2009 there was a dramatic decrease in sedge species cover. There seems to be more changes in bryophyte cover in mesotrophic sites than in ombrotrophic ones. The hummock-specific Sphagna seem to be resilient to WT drawdown. Especially lawn- and hollow-specific bryophytes responded to WT drawdown. Results show that all plant groups have a different short and long term response to water level drawdown. The first three years after ditching appeared to be a disturbance state. Only after that the vegetation started to adapt to the lowered water table conditions.
  • Kokko, Aira; Ojanen, Paavo; Aapala, Kaisu; Hotanen, Juha-Pekka; Laitinen, Jarmo; Punttila, Pekka; Rehell, Sakari; Tiainen, Juha; Vasander, Harri (Suoseura, 2020)
    Suo 71(2): 149–155 (2020)
    Suoluonnon muutosten takia monet soiden luontotyypit ovat uhanalaistuneet. Vuonna 2018 valmistuneessa Suomen luontotyyppien uhanalaisuuden arvioinnissa suoluontoa tarkasteltiin ja arvioitiin kahdella hierarkiatasolla. Yhtäältä tarkasteltiin suokasviyhteisöjä, joita voidaan luokitella suotyypeiksi. Toisaalta tarkasteltiin useiden suotyyppien muodostamia laajempia suokokonaisuuksia eli suoyhdistymiä sekä useista erillisistä suolaikuista muodostuvia maankohoamisrannikon soiden kehityssarjoja (Kaakinen ym. 2018a, b). Soiden luokiteltuja kasviyhteisöjä kutsutaan suotyypeiksi (Eurola ym. 2015, Kaakinen ym. 2018b, Laine ym. 2018). Yhdellä suolla on yleensä useiden, jopa kymmenien eri suotyyppien kasvillisuutta. Suokasviyhteisöjen pääryhmiksi katsotaan kasvitieteellisessä suoluokittelussa korvet, rämeet, nevat ja letot, mutta myös luhtaja lähdekasvillisuus (Eurola & Kaakinen 1978, Eurola ym. 2015, ks. Soiden kasvillisuus). Luhdat ja lähteiköt vaihettuvat ilman selvää rajaa vesiluontotyyppeihin. Luontotyyppien uhanalaisuusarvioinnissa lähteikköluontotyypit on käsitelty ja arvioitu sisävesiluontotyyppien yhteydessä (Lammi ym. 2018). Luhdat ja lähdekasvillisuus mainitaan myös uusimmissa metsätieteellisissä suotyyppioppaissa (esim. Laine ym. 2018). Eri päätyyppiryhmiin kuuluva suokasvillisuus muodostaa myös yhdistelmätyyppejä: neva- ja lettokorpia sekä neva- ja lettorämeitä. Suoyhdistymä on yhtenäinen suoalue, jossa on eri suotyypeistä koostuvia osia (Ruuhijärvi 1960, Eurola 1962, Kaakinen ym. 2018b). Suoyhdistymätyypit jakautuvat ilmastollisiin ja paikallisiin tyyppeihin. Ilmastollisista suoyhdistymätyypeistä keidassoiden eli kohosoiden esiintyminen painottuu eteläisen Suomen muuta Suomea kuivempaan ja lämpimämpään ilmastoon, kun taas aapasoiden esiintyminen painottuu pohjoisen Suomen kosteaan ja viileään ilmastoon (Ruuhijärvi 1960, Eurola 1962). Myös rinnesuot vaativat viileän ja kostean ilmaston (Havas 1961), ja palsasoita esiintyy vain pohjoisimmassa Lapissa, missä on tarpeeksi kylmää paikallisen ikiroudan syntymiselle (Kaakinen ym. 2018b). Paikallisia suoyhdistymätyyppejä ovat rannikkosuot, boreaaliset piensuot ja tunturisuot, joiden ominaispiirteet ja esiintyminen riippuvat enemmän paikallisista olosuhteista kuin ilmastosta (Kaakinen ym. 2018b). Maankohoamisrannikon soiden kehityssarjoja syntyy, kun maata kohoaa Pohjanlahden rannikolla vähitellen merenpinnan yläpuolelle (Rehell ym. 2012, Laitinen 2013). Sarjan nuorimmat suot lähinnä meren rantaa ovat tyypillisesti luhtia ja vanhimmat suot ovat kehittyneet aapa- tai keidassoiksi (Kaakinen ym. 2018b).
  • Paasio, Ilmari (Suomen metsätieteellinen seura, 1936)