Papers by Hannu Ilvesniemi
On a European scale, the critical load concept has been generally accepted as the basis for abate... more On a European scale, the critical load concept has been generally accepted as the basis for abatement strategies to reduce or prevent damage to the functioning and vitality of forest ecosystems caused by transboundary acidic deposition. The aim of this paper is to review the ...
Boreal Environment Research, 2008
Podzol horizons (O, E, B1, B2 and C) from three undisturbed sites were analyzed for phosphorus (P... more Podzol horizons (O, E, B1, B2 and C) from three undisturbed sites were analyzed for phosphorus (P) sorption, P saturation, P fractions, and P concentrations in soil solutions, and three disturbed Podzols for P in soil solution. The threshold concentrations for net sorption were 8000 μg l–1 and 700 μg l–1 for the O and E horizons, respectively, and 3–6 μg l–1 for the B1, B2 and C horizons. Consequently, if water percolates through the B horizon the risk of P leaching is low. Phosphorus saturation degree was 0.2%–25%. Fe-P dominated in the O, E, B1 and B2 horizons, and Ca-P in the C horizon. P was depleted from the E horizon (24 μg g–1) and enriched in the B1 and B2 horizons (500 and 250 μg g–1) as compared with that in the C horizon (160 μg g–1). P in soil solution increased in the topmost 3 cm of the disturbed B horizons.
The relationship between production and decomposition determines whether a forest site is a sink ... more The relationship between production and decomposition determines whether a forest site is a sink or a source of atmospheric CO2, but the absolute or relative contributions of photosynthetic and respiratory fluxes in forests managed in different ways are not yet well known. Forest harvesting reduces the amount of the living stand biomass and the corresponding amount of accumulated atmospheric carbon while the amount of recent plant litter increases. In addition to clear-cutting and residue removal, the site preparation also affects the decomposition conditions of the soil organic matter. The soil CO2 efflux of each treatment replicate was measured from 6 spots within every above described treatment area. The spots that were chosen represented: 1. Undisturbed microsites (resembling ground vegetation and humus before treatment) 2. Disturbed microsites (ground vegetation and humus clearly affected by harvesting operation), 3. Mounded microsites (soil preparation leaving no vegetation or...
Metsätieteen aikakauskirja, 2018
Suomen Maataloustieteellisen Seuran Tiedote, 2014
Paineistetulla kuumavesiuutolla puusta pystytään eristämään vesiliukoinen hemiselluloosafraktio. ... more Paineistetulla kuumavesiuutolla puusta pystytään eristämään vesiliukoinen hemiselluloosafraktio. Aikaisempien tutkimusten perusteella puusta eristetty hemiselluloosa soveltuu märehtijöiden rehuksi. Prosessista tuleva hemiselluloosa on vesiliuoksessa, jonka kuivaaminen on kallista. Uutteen yhtenä käyttövaihtoehtona voisi olla hemiselluloosaliuoksen (hemiliuoksen) juottaminen sellaisenaan. Tässä kokeessa selvitettiin, miten maittavaa hemiliuos on lypsylehmille ja millaisia määriä vuorokaudessa lehmät sitä juovat. Kuumavesiuutot suoritettiin Metlassa Vantaalla. Uuttolämpötila oli 180 °C kuuselle ja 170 °C koivulle ja virtausnopeus uuton aikana oli 20 l minuutissa. Hemiliuosten maittavuuden selvittämiseksi tehtiin juottokoe kuudella lypsylehmällä MTT Maaningan tutkimusnavetassa tammikuussa 2013. Lehmät olivat parsissa ja niiden seosrehun kulutus ja maitomäärä mitattiin päivittäin. Kokeen alussa 2,5 päivän ajan selvitettiin lehmäkohtaisesti päivittäinen vedenkulutus. Kolmantena koepäivän...
Acta Forestalia Fennica, 1998
Metsätieteen aikakauskirja, 2007
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Papers by Hannu Ilvesniemi