Artikkelit jotka sisältää sanan 'site'
Suomen aapasuoalueen välipintakoivulettojen, Warnstorfii-lettojen ja lettokorpien analyysi: lajistogradientit, tyyppivariantit ja makrotopografia.
English title: Analysis of drier rich Betula pubescens fens, rich Sphagnum warnstorfii fens and rich Picea abies mires in the aapa mire area of Finland: compositional gradients, type variants and macro-topography.
Original keywords:
habitaattityypit;
korpisuus;
lähteisyys;
Saxifrago-Tomentypnion;
Sphagno warnstorfii-Tomentypnion;
suotyypit
English keywords:
mire site types;
groundwater influence;
habitat types;
Saxifrago-Tomentypnion;
Sphagno warnstorfii-Tomentypnion;
species composition of Picea abies mires
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Letot ovat Suomen uhanalaisinta suokasvillisuutta. Niiden luokittelu botaanisiin suotyyppeihin, uhanalaisuusarvioineissa käytettyihin habitaattityyppeihin ja mannertason levinneisyysarvioissa käytettyihin Braun-Blanquet tyyppeihin on tärkeää, jotta erilaisten lettojen uhanalaisuusaste ja suojelutarve osataan arvioida. Pääosa letoista on ruskosammalvaltaisia. Lettojen luokittelu suotyypeiksi muutaman valtasammalen mukaan on paljolti jopa nevojen luokittelua selkeämpi. Sen sijaan rahkasammalvaltaisen, Sphagnum warnstorfii-rikkaan lettokasvillisuuden suomalainen luokittelu – Warnsorfii-letot, lähdeletot, välipintakoivuletot ja lisäksi runsaspuustoisemmat lettokorvet – perustuu vain pieniin lajistollisiin eroihin ja muodostaa siten epävarmuustekijän luokittelussa. Testasimme Ruuhijärven (1960) klassisesta kasvillisuusaineistosta Peräpohjolan ja Pohjanmaan aapasuoalueen ´kuivempien koivulettojen´, Warnstorfii-lettojen ja lettokorpien luokittelua klusterianalyysin avulla. Ordinaation avulla tarkastelimme aineiston päävaihtelusuuntia sekä vertasimme klustereiden sijoittumista suhteessa alkuperäisiin suotyyppeihin. Klusterit nimesimme indikaattorilajianalyysista saatujen tunnusomaisimpien lajien avulla. Käytimme ensin kolmen klusterin optiota suotyyppien määrän mukaan, mutta klusterit eivät rinnastuneet suotyyppeihin. Suotyyppitulkinnan kannalta seuraavan jakotason alaklusterit osoittautuivatkin hedelmällisiksi; kuvasimme ne erotuslajien avulla suoraan kasvillisuustaulukosta. Uudet klusterit saatoimme tulkita suokuvion pinnan makrotopografian ja purkautuvan pohjaveden määrän suhteen: laakeisiin lähdekumpuihin liittyy oma kasvillisuusyksikkönsä ja habitaattityyppinsä, jolloin varsinainen välipintakoivuletto kapenee alkuperäisestä (tasainen suurmuoto, koivuisuus). Analyysissä erottuivat lisäksi Warnsorfii-leton keskustavaikutteinen variantti (tasainen, puuton) ja Warnstorfii-leton reunavaikutteisesta variantista ja lettokorvesta muodostunut kasvillisuusyksikkö, jollainen kasvillisuus pääosin sijoittuu maastoon kaikista edellisistä poiketen alla olevan kivennäismaan topografiaa mukaillen. Viimemainittu testiyksikkö myös osoitti, että hyvin samantapaista kasvillisuutta voi olla niin puustoisessa kuin avosuohabitaatissakin. Warnstorfii-leton kahden variantin sijoittuminen testiluokittelussa kauas toisistaan korostaa habitaattityypittelyyn ennestään sisältyvää luokitteluongelmaa, jossa ´välipintaletto´ (Campylium-letto ja Warnstorfii-letto yhdessä) käsittää epäsuhtaisen suuren vaihtelualan suhteessa välipintakoivulettoon. Braun- Blanquet tyypittelyn kannalta Ruuhijärven lettokorpinäytealasarjalla (auktorimerkintä Braunmoorbrücher Ruuhijärvi 1960) on korvaamaton merkitys, koska tyyppi on vielä systeemissä luokittelematta.
Katsaus turvetuotannosta vapautuvien suonpohjien jälkikäyttömuotoihin, sekä niiden ympäristö- ja monimuotoisuusvaikutuksiin.
PK-lannoituksen vaikutus männyn ravinnetilaan Pohjois-Pohjanmaan ojitusalueilla.
English title: Long-term nutrient status of PK fertilized Scots pine stands on drained peatlands in North-Central Finland.
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The low availability of usable phosphorus (P), as well as the scarcity of potassium (K), are often limiting tree growth on peatlands. Approximately one third of the 5.5 million ha of peatlands drained for forestry in Finland has been fertilized during the last 50 years. The aim of this study was to determine the long-term effect of PK fertilization on the nutrient status of Scots pine on different site types of drained peatlands. Changes in nutrient concentrations (N, P, K) and dry mass of current needles was used for examining the effect of fertilization. The material included 82 fertilization experimental stands comprising a total of 892 needle samples; 434 from PK-fertilized and 458 from unfertilized control stands. The needles were collected and analyzed between 1980 and 2002. Depending on the experiment, a time period of 1–35 years had elapsed between fertilization and needle sampling. More than half (54%) of the control stands had P concentration below the defi ciency limit 1.3 mg g–1, and correspondingly, 48% had K concentration below 4.0 mg g–1. Fertilization increased considerably the needle dry mass and foliar P and K concentration raised above the deficiency limits. The lower the concentrations of foliar P and K and the higher the concentration of N were in control trees, the more pronounced the effect of PK fertilization was. Compared to control, the needle P concentration was still noticeably higher on the fertilized stands after 21–35 years of the fertilization. However, K concentration had decreased and was at the same level as in the control trees. The effect of fertilization was strongest on sites which had been treeless or sparsely forested before drainage and which had severe nutrient shortages or imbalances. The response to fertilization was very similar regardless of the temperature sum of the year the needles first appeared. The results of this study show that the P status of Scots pine could be improved for over 30 years with single fertilization. On the other hand, ensuring the K status will require 1–2 refertilization treatments during the rotation period.
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Silfverberg,
Finnish Forest Research Institute, Vantaa Research Unit, P.O. Box 18, FI-01301 Vantaa
Sähköposti:
ei.tietoa@nn.oo
- Moilanen, Sähköposti: ei.tietoa@nn.oo
Arokosteikot: ekologia, esiintyminen ja suojelutilanne Pohjois-Pohjanmaalla ja Kainuussa.
English title: Aro wetlands: ecology, occurrence and conservation in north-central Finland.
Avainsanat:
Nature conservation;
aapa mire;
ecological gradient;
Finnish mire site type system;
groundwater;
mire complex;
peatland morpology;
seasonal drought;
wetland classification
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The present paper introduces and describes a poorly known wetland type – aro wetland – in well permeable mineral soil substratum in Northern Ostrobothnia and Kainuu (between 64° – 66° N lat.). Field observations (linked with the interpretation of aerial photographs) were made in 32 localities, whose conservation status is presented. We define boreal aro wetlands ecologically as a seasonal wetland type of their own which occur on well-drained mineral soil, which are mainly characterised by treeless, mire expanse fen vegetation and in which the peat accumulation is (almost) totally hampered by the vigorous decomposition of the organic matter resulting from an extremely unstable water regime (flood and seasonal drought) and small plant production. Aro wetlands in the western part of the study area occur on sandy substratum (the largest in parts of mire complexes split by ancient raised beach ridges), whereas in the eastern part the aro wetlands known so far are small pond-like depressions in till substratum. Carex lasiocarpa (mostly) dominates the vegetation on sandy substratum. Juncus filiformis and Carex nigra are typical, and Rhynchospora fusca and Molinia caerulea a bit rarer. Sphagnum cover is usually minimal. Considering aro wetlands an extreme case of suo (mire) makes the stability of water regime (stable – unstable) a direction of variation in the traditional Finnish mire site type system, which is based on several ecological gradients.
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Laitinen,
University of Oulu, Department of Biology, Botany, P.O.Box 3000, FI-90014, Finland
Sähköposti:
ei.tietoa@nn.oo
- Rehell, Sähköposti: ei.tietoa@nn.oo
- Huttunen, Sähköposti: ei.tietoa@nn.oo
- Eurola, Sähköposti: ei.tietoa@nn.oo
Kunnostusojitustarpeen ennustaminen ojitusalueilla.
English title: Predicting the need for ditch network maintenance in drained peatland sites in Finland.
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Logistic regression models were developed to predict the condition of ditch networks in drained peatland sites in Finland. The data consisted of observations from two forest inventories in which the need for ditch network maintenance had been assessed in the field by classifying the condition of the ditches in the sample stands. In the analysis an indicator variable which referred to one of two condition categories (in need of repair – not in need of repair) was used as the response variable. According to the results, the probability of being in the poor condition category was higher in sites where the time elapsed since drainage was longer, the geographic location was more northern, peat thickness was greater, and plot inclination was smaller. At a probability level of 0.5, the models predicted the category correctly in 69% of the sites in the modeling data, on average. The models were applied to a growth simulator to study the effect of poor drainage conditions on stand-level growth forecasts.
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Hökkä,
Finnish Forest Research Institute, Rovaniemi Research Station, P.O. Box 16, FIN-96301 Rovaniemi, Finland
Sähköposti:
ei.tietoa@nn.oo
- Alenius, Sähköposti: ei.tietoa@nn.oo
- Salminen, Sähköposti: ei.tietoa@nn.oo
Pituusboniteettisovellus ojitusalueiden metsille.
English title: Site index model approach for drained peatland forest stands.
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The site index system presented is intended as support for the idea of developing a more hierarchical and integrated forest classification system in Finland. The data used were obtained from stands growing on old permanent experimental plots laid out in drainage areas in southern Finland. The model, describing the post-drainage development of stand dominant height as a function of drainage age (time elapsed since drainage), is based on successive measurement data (465 observations), collected from 89 plots, each representing a single stand. The site indices H40dr are post-drainage dominant height values 40 years since drainage, given in 2-meter classes. Post-drainage dominant height is defined as the difference between the current dominant height and the dominant height at the time of drainage. In classification work, one needs to know (or measure) the two aforementioned height characteristics, together with age since drainage. If the dominant height at the time of drainage is not known, it can be estimated from a function presented herein and based on current dominant height and drainage age. The mean annual volume increments at 40 years since drainage (MAI40) are also presented. There is still a need for examining separately the accuracy of the model with new data from spruce-, pine- and birch-dominated stands, collected for numerical constructions of site index curves. Therefore, the site index model and its characteristics must be seen more as outlines than as a final system for practical application. A well-functioning ditch network is a default when applying the site index curves.
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Gustavsen,
The Finnish Forest Research Institute, Joensuu Research Station, P.O.Box 68, FIN-80101 Joensuu, Finland
Sähköposti:
ei.tietoa@nn.oo
Carbon storage response to harvesting and site preparation in a forested mire in northern Michigan, U.S.A.
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This study considered the effects on carbon pools in a forested mire following whole-tree harvesting and two site preparation treatments; bedding and trenching. Whole-tree harvesting, which resulted in complete removal of the overstory biomass, and bedding exhibited the greatest loss of carbon from the site. Removal of the overstory biomass and increased decomposition of organic matter were the major causes of carbon loss. Measurement of the soil carbon pools in the tree planting zone did not provide an accurate assessment of the treatment effect. Renewal of carbon accumulation will depend on the productivity and composition of the regenerating plant community and on the rate of decomposition of organic matter.
Keywords: Decomposition, organic matter, site preparation, whole-tree harvest
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Trettin,
Environmental Sciences Division, Oak Ridge National Laboratory, P.O. Box 2008 MS-6038, Oak Ridge, 77V 37831-6038 U.S.A
Sähköposti:
ei.tietoa@nn.oo
- Gale, Sähköposti: ei.tietoa@nn.oo
- Jurgensen, Sähköposti: ei.tietoa@nn.oo
- McLaughlin, Sähköposti: ei.tietoa@nn.oo
Esimerkki pseudolajien runsauskynnysten muuntelun vaikutuksesta TWINSPAN-Iuokittelussa.
English title: The effect of pseudospecies cut level settings on the results of TWINSPAN classification.
Avainsanat:
drained peatlands;
mire classification;
vegetation;
mire site type;
multivariate analysis
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TWINSPAN classifications of the same drained mire vegetation data using four different pseudospecies cut level scales were compared. The material consisted of 96 sample plots located on drained spruce and pine mires in eastern Finland. The pseudospecies cut level scales were the octave scale (0, 0.5, 1, 2, 4, 8, 16, 32 and 64%), a coarse scale (0, 5, 10, 20 and 50%), TWINSPAN default settings (0, 2, 5, 10 and 20%), and presence/absence. The classificatons were quite similar at the first division but they differed markedly from each other at the final third division showing that the choice of cut levels has an important effect on TWIN-SPAN results. The sample plots in one TWINSPAN cluster defined with set of cut levels were allocated to several clusters defined with other cut level settings. The presence/absence setting resulted in a classification which was the most different from the classification made using the default settings. The TWINSPAN classifications performed using the default and octave scale settings corresponded the best with the field classification of the plots and were ecologically the most interpretable.
Keywords: Drained peatlands, mire classification, mire site type, multivariate analysis, vegetation
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Hotanen,
The Finnish Forest Research Institute, Joensuu Research Station, P.O. Box 68, SF-80101 Joensuu, Finland
Sähköposti:
ei.tietoa@nn.oo
Turvesaannon arviointi suotyypin ja turpeen syvyyden perusteella.
English title: Estimation of peat yield of different peat deposit types.
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Preliminary regression models are produced for the estimation of dry peat yield (tons) per unit area (hectare) for different types of peat deposits with different peat thickness. The models are based on 6 500 peat samples obtained for bulk density measurements from 245 vertical peat profiles (70 virgin and drained peadands) in Finland. In general, the increase in the peat yield does not take place in 1:1 relationship with depth because average bulk density tends to decrease with peat deposit thickness. Fairly reliable estimates of the peat yield using depth and mire site type were obtained. R2 values for the eight models representing eight different groups of "mire site types" ranged from 86.0 to 95.3%.
Keywords: Bulk density, mire site types, peat deposits, peat resources
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Tolonen,
Department of Biology, University ofJoensuu, P.O. Box 111,SF-80101 Joensuu, Finland
Sähköposti:
ei.tietoa@nn.oo
- Ijäs, Sähköposti: ei.tietoa@nn.oo
Suoekosysteemin toiminnallinen ryhmitys.
English title: The functional grouping of mire ecosystems and their response to drainage.
Avainsanat:
mire classification;
mire site types
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The results of inventories of drained peatlands have occasioned criticism of profitless drainage. For the better understanding of the mire ecosystem a functional and structural division of mires is presented. This is based on the nutrient cycle, the mire margin — mire expanse-effect, the carbon balance and the community structure of mire sites. The suitability for drainage is discussed on the basis of the ecology. A suggestion is made for further treatment of drained mire complexes.
Keywords: Mire classification, mire site types
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Eurola,
Department of Botany, Oulu University, SF-90570 Oulu, Finland
Sähköposti:
ei.tietoa@nn.oo
- Huttunen, Sähköposti: ei.tietoa@nn.oo
Korpirämeet ja karut korvet suomalaisissa suoluokitusjärjestelmissä.
English title: The place of spruce-pine mires and oligotrophic spruce mires in Finnish peatland site type classifications.
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In Finland three different mire classification systems can be distinguished: 1) those for ecological purposes based on detailed botanical surveys, 2) those for scientific forestry research purposes, and 3) more extensive systems for practical forestry purposes. All systems are based upon Cajan-der's site-type principle whereby habitats which are ecologically similar are considered to support a similar vegetation. The classification (site type names, analogy/correspondence, nutrient status level) of spruce-pine mires and oligotrophic spruce mires according to the above-mentioned systems is compared. Some criticism concerning especially the confusing naming of the same type is presented. The varying post-drainage suc-cession in these site type groups is also discussed. Finally an attempt to distinguish the more oligotrophic spruce-pine mires from the less oligotrophic ones is made.
Keywords: Drainage, mire classification, site type, succession, trophy
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Hotanen,
The Finnish Forest Research Institute, Joensuu Research Station, P.O. Box 68, SF-80101 Joensuu, Finland
Sähköposti:
ei.tietoa@nn.oo
Metsäojitettujen soiden kasvupaikkaluokituksen suunnanhakua.
English title: The need of improving the site classification of mires drained for forestry.
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A review of the historical development of mire site classification in Finland with special emphasis on the studies and theories of post-drainage succession is made. Some criticism of the prevailing classification system is presented and a work model for guiding further study of drained mire classification is proposed. Preliminary results of a new approach to classify the vegetation of old peatland forests using TWINSPAN classification and DCA ordination techniques are presented.
Keywords: Drainage, mire classification, site type, succession
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Reinikainen,
The Finnish Forest Research Institute, Department of Peatland Forestry, P.O. Box 18, SF-01301 Vantaa, Finland
Sähköposti:
ei.tietoa@nn.oo
Koillis-Kiinan suot ja niiden hyväksikäyttö.
English title: Peatlands and their utilization in northeast China.
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Peatlands complexes, site type classification and utilization of peatlands in northeast China are reviewed. The number of mire plant species common to both Finland and northeast China is about 120. Peatlands have been reclaimed for agriculture for a long time, but amelioration for forestry is only in the beginning. However, the potential of peatlands for forestry after drainage is considered high.
Keywords: China, peatland complexes, peatland site types, peatland utilization.
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Zhao,
Changchun Institute of Geography, Chinese Academy of Sciences, People's Republic of China
Sähköposti:
ei.tietoa@nn.oo
- Päivänen, Sähköposti: ei.tietoa@nn.oo
Quebecin soista ja metsäojitustoiminnasta.
English title: Peatlands and forest drainage in Quebec, Canada.
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The interest in peatland forestry in Quebec is increasing as the peatlands of the St-Lawrence valley are considered to have a good drainage response capacity A relatively important forest drainage project is being carried out on a practical scale. However, the lack of a practically oriented peatland classification system is an important drawback. This paper is an attempt to produce a preliminary classification system intended for practical peatland forestry.
Keywords: Quebec, forest drainage, site type classification.
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Schneider,
University of Helsinki, Department of Peatland Forestry, Unioninkatu 40 B, SF-00170 Helsinki, Finland
Sähköposti:
ei.tietoa@nn.oo
Puuntuotannon ja puunhankinnan kehittämismahdollisuudet Etelä-Lapin ojitetuilla soilla.
English title: The development opportunities of silviculture and wood procurement on drained peatland forests in southern Lapland, Finland.
English keywords:
Drainage;
ditching;
site type;
harvesting;
thinning;
tree species;
carrying capacity;
forest management
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