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Preserving streamside forest habitats or buffer strips is considered to reduce forestry-related biodiversity loss in commercial forest landscapes. However, it is still unclear what type of management in and near streamside forests can be undertaken without compromising their biodiversity and natural change through succession. Using a before–after, control–impact study design, we tested the impacts of forested buffer strips (15 or 30 m wide, with or without selective logging), preserved after clear-cutting, on the changes of polypore communities in streamside boreal forests in Finland. Manipulations in 28 sites produced four treatment classes, the community compositions of which were compared with seven unmanaged controls before and 12 years after the manipulations. The polypore community composition in 15 m wide buffer strips changed differently than that in controls and resembled the community composition typically found in production forests. Moreover, selective logging tended to homogenize polypore communities. These responses of polypore communities indicate that the natural biodiversity and succession of streamside forests was disturbed in both 15 m wide and selectively logged buffer strips. Streamside forests in nonlogged 30 m wide buffer strips seemed to retain the natural polypore community composition and succession, at least during the 12-year period.

Three geometrical thinning methods were tested and compared with conventional selective thinning. The geometrical harvesting methods were two boom corridor (BCT1, BCT2) and one machine corridor (MCT) methods. In the BCT-methods all trees were removed from 1.5 m wide and 10 m deep corridors which were placed on both sides of the trip road at each operational stop. In BCT1, three corridors were made on both sides of the machine at various angles to the travel direction at each operational stop at 10 m intervals. In BCT2, corridors were made only at a 60° angle and 3 m intervals. In the MCT trees were removed only from the front of the machine. BCT2 had the highest productivity in harvesting, forwarding and overall productivity (3.96 m3/E0). The selective thinning was even in harvesting but lower in forwarding and overall productivities (3.82 m3/E0). BCT1 productivity was lower in harvesting and forwarding with 3.68 m3/E0 overall productivity. In the MCT the dense treetops in front of the machine oft...

Ennallistamisen tavoitteena on nopeuttaa talousmetsäkäytössä olleen boreaalisen metsän palautumista rakenteeltaan, toiminnaltaan ja eliöstöltään luonnontilaisen kaltaiseksi. Ennallistamistoimilla, kuten lahopuun määrän lisäämisellä tai kulotuksella, pyritään jäljittelemään metsän luontaisia häiriöitä, kuten tuulenkaatoja tai metsäpaloja. Intensiivisen metsänhoidon piirissä olevaan tasaikäiseen ja vähälajiseen metsään ihmisavusteinen häiriö, kuten lahopuun lisääminen ja/tai kulotus, luo monimuotoisempaa rakennetta ja uutta kasvutilaa. Tämän tutkimuksen tavoitteena oli testata maakiitäjäisten vasteita ennallistamistoimiin, kun ennallistamisesta oli kulunut seitsemän vuotta eli hieman pidempi aika kuin useimmissa metsän ennallistamista koskevissa tutkimuksissa. Tutkimuksen kohteena toimivat kuoppapyydyksin pyydystetyt maakiitäjäis-heimon kovakuoriaiset (Coleoptera: Carabidae), koska ne ovat ekologisesti hyvin tunnettu ryhmä ja niiden tiedetään vastaavan herkästi metsänhoitotoimenpiteiden aiheuttamiin elinympäristön muutoksiin. Tutkin ennallistamisen vaikutuksia maakiitäjäisten yhteisörakenteen vaihteluun tutkimusaloilla, joita oli kulotettu, harvennettu ja jätetty erilaiset määrät maapuuta. Lisäksi huomioin tutkimusalojen sisällä olleen kosteusgradientin. Tämän tutkimuksen perusteella maakiitäjäislajisto vaikutti selvinneen ennallistamistoimenpiteistä ts. häiriöistä kohtalaisen hyvin. Tarkempaa tarkastelua varten jaoin lajiston metsän latvuskerroksen sulkeutuneisuuden mukaan metsä-, avomaa- ja generalistilajeihin. Metsälajisto oli säilynyt parhaiten alojen kosteilla ruuduilla, mutta avomaa- ja generalistilajisto näyttivät yleisesti hyötyneen häiriöistä. Kulolajistoa ei löytynyt, joten edes voimakkaimmin palaneet alat eivät tarjonneet niille sopivia resursseja. Luontaisiin häiriöihin sopeutuneet lajit voivat hyötyä mutta metsien herkimmät lajit kärsiä ennallistamisesta, joten metsän historia, rakenne ja lajisto täytyy tuntea ennen ennallistamistoimiin ryhtymistä. Tutkimuksessa saatua tietoa lajien vasteista häiriöihin voidaan hyödyntää metsän ennallistamisessa. Kuitenkin tulosten yleistettävyydestä muihin lajiryhmiin sekä häiriöiden ja ennallistamistoimien pitkäaikaisista vaikutuksista tarvitaan lisää tietoa.

The simulation model consists of a method to generate theoretical Norway spruce ( (L.) H. Karst.) stands, and a spatial growth model to predict the growth of these stands. The stand generation procedure first predicts the tree diameters from a few stand characteristics and from tree locations. Tree age and height are predicted using spatial models. Spatial growth models were made for both diameter growth and basal area growth. Past growth was used as a predictor in one pair of models and omitted in another pair. The stand generation method and the growth models were utilized in studying the effect of tree arrangement and thinning method on the growth of a Norway spruce stand.Picea abies

This paper analyses the nutrient loses caused by whole-tree harvesting on the basis of the literature data. It has been considered that traditional stemwood harvesting does not lead to impoverishment of the soil because the nutrient content of the wood is quite low. The nutrient loss occurring in connection with heavy thinnings and whole-tree harvesting has been considered so great that it has to be compensated by fertilizer application. In comparison with harvesting unbarked stem timber, whole-tree harvesting has been found to increase the nutrient loss at the stage of final cutting as follows: N2 to 4 times, P 2 to 5 times, K 1.5 to 3.5 times and Ca 1.5 to 2.5 times. Depending on the conditions prevailing on the site, any one of these nutrients may be the limiting factor for tree growth during the next tree generation. The PDF includes a summary in Finnish.

The radial growth of Scots pine ( L.) stands at the age 30â40 years was measured retrospectively five years after the fertilizing and thinning of the stands. The abrupt effect of fertilizing was culminated 3â4 years after the treatment. The effect of thinning increased throughout the monitoring period. In stands that had been both thinned and fertilized, the effect of thinning was covered almost entirely by the effect of fertilizing, but fertilizing and thinning gave greater response than applying fertilizer or thinning only. Pinus sylvestris

Ensimmäinen painos ilmestynyt nimellä Metsän hoitohakkauksista (1931)

kuvitti Aarno Liuksiala