Publikasjoner
NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.
2001
Sammendrag
Foliage nutrient concentrations of overstorey and understorey Norway spruce (Picea abies (L.) Karst.), and height growth and needle weights of understorey saplings, were studied in a seven-year period after harvest. The following treatments were applied on each of three sites five years prior to needle sampling: control with no cutting, partial cutting with 50-60 % removal of basal area, and patch cut (25 x 25 m - 0.063 ha clear-cut). Saplings on control plots had higher concentrations of K and Cu in current-year needles (C) than overstorey trees. Increased harvest intensity led to a reduction of K in C- needles and Mg in (C+1)-needles of saplings, and of B in both saplings (C, C+1) and overstorey trees (C+1). Sapling needle weights generally increased with harvest intensity, whereas no effect of foliage N status on needle weights could be detected. The growth response of saplings was explained by the interaction between foliage N status, quantified as average N concentration in C- and (C+1)-needles, and harvest intensity. The results illustrate that sufficient N supply is a key factor for the ability of advance regeneration to utilize the improved light condition associated with overstorey removal.
Sammendrag
Injuries and mortality to advance growth (saplings) after selection harvesting was studied in 17 multi-storied Norway spruce (Picea abies (L.) Karst.) stands. Harvest removals ranged from 33 to 67 % of initial basal area. Four of the stands were harvested motor-manually (chain saw + skidding with farm tractors; M-FT). The remaining stands were harvested with single-grip harvesters and forwarders (H-FW). In each stand, injury rates were evaluated on a 24x48 m plot, located between the centrelines of two parallel striproads that were spaced 24 m apart. All logging teams had at least five years of experience in clear-cutting and thinning operations. The trees to be removed, and striproad centrelines, were marked prior to harvest. Mortality varied between 5 and 51 %, whereas total injury (injured + dead saplings) varied between 17 and 76 %. Mortality- and injury levels were generally highest on H-FW plots. Crown reduction and leaning stems were the most frequent types of injury, regardless of operating method. Injury rates increased with sapling height with the H-FW method, whereas the opposite was found on M-FT plots. Saplings without pre-harvest damage in the form of top- or leader defects had a higher probability of being injured than saplings with such damage in stands harvested with the M-FT method. A similar difference was not found on H-FW plots. A logistic regression model show that the spatial risk for injury depends on the interaction between forest condition factors and operational characteristics. Forest condition factors influencing the risk of injury are sapling height and the location of saplings relative to larger residual trees and striproads. Corresponding operational characteristics are operating method and harvest intensity.
Forfattere
Tove M. Østensvik K. Myhre A. SchaugSammendrag
Det er ikke registrert sammendrag
Forfattere
Petter NilsenSammendrag
Det er ikke registrert sammendrag
Forfattere
Anders Göransson Toril Drabløs EldhusetSammendrag
The results strongly suggest that the growth rate of N. spruce is not correlated with the basecation/Al ratio in the rooting medium, but with the basecation/nitrate ratio
Forfattere
Tor J. JohansenSammendrag
Det er ikke registrert sammendrag
Forfattere
Tor J. JohansenSammendrag
Det er ikke registrert sammendrag
Forfattere
Tor J. JohansenSammendrag
Det er ikke registrert sammendrag
Forfattere
Tor J. JohansenSammendrag
Det er ikke registrert sammendrag
Forfattere
Tor J. JohansenSammendrag
Det er ikke registrert sammendrag