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.
2008
Sammendrag
We investigated whether the stand age affects the life span of tree and understory fine roots (<1mm) in three Norway spruce (Picea abies) stands: 30, 60 and 120-yr-old. In each stand 9 minirhizotrons were installed and images were collected once in a month throughout the growing season during the three years. Norway spruce fine roots in the 30-yr old stand had a life span 401 ± 27 and 341 ± 68 days, and understory 409 ± 162 and 349 ± 142 days, estimated by using the Kaplan Meier survival analysis (KM) and Weibull distribution, respectively...
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Manipulation of the canopy cover and site preparation are the most important silvicultural measures to enhance the conditions for natural regeneration of Norway spruce (Picea abies (L.) Karst.). During the early regeneration phase however, seedling mortality may be high, so it is important to study how different combinations of stand-level treatments and site preparation methods affect seedling establishment. We studied emergence, 1st winter and 2nd summer mortality for naturally regenerated spruce seedlings in a field experiment that combined four harvest treatments (shelterwoods of high (SH), medium (SM) and low (SL) residual basal area, and a 50 x 50 m clear-cut (CC)) and two site preparation methods (patch scarification and inverting). The CC had significantly fewer seedlings the 1st fall than the SL and SH (p = 0.0377), and in all harvest treatments, fewer seedlings emerged in inverted than in patch scarified spots (p = 0.0351). Mortality was also lower with patch scarification than inverting (1st winter: p = 0.0565, 2nd summer: p = 0.0377), but was not affected by harvest treatment (1st winter: p = 0.9211, 2nd summer: p = 0.1896). On average, mortality from 1st to 2nd fall reached 38% and 27% after inverting and patch scarification, respectively. First winter mortality accounted for approximately two thirds of the accumulated mortality, regardless of the harvest treatment and site preparation method.
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
The relationships between measures of forest structure as derived from airborne laser scanner data and the variation in quantity (Q) and vitality (V) of young trees in a size-diverse spruce forest were analyzed. A regeneration success rate (Q), leader length (V), relative leader length (V), and apical dominance ratio (V) were regressed against 27 different laser-derived explanatory variables representing three different spatial scales. The resulting 81 different models for each response variable were ranked according to their Akaike information criterion score and significance level. Each laser variable was then associated with four categories. These were scale, return, fraction, and type. Within the scale category, laser variables were grouped according to the spatial scale from which they originated. Similarly, within the return, fraction, and type categories, the variables were grouped according to if they originated from first or last return echoes; if they originated from lower, middle, or upper fraction of the range of laser heights or values derived from the full range of laser pulses, and if they were canopy height or canopy density metrics. The results show that the laser variables were strongest correlated with the quantity of small trees and that these variables could be attributed to large-scale, last return, lower fraction, and density metrics. The correlations with the vitality responses were weaker, but the results indicate that variables derived from a smaller scale than for the quantity were better in order to explain variation in leader length, relative leader length, and apical dominance ratio. (C) 2007 Elsevier B.V. All rights reserved.
2007
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Svein SolbergSammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag