Hopp til hovedinnholdet

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

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.