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.
2004
Forfattere
Peder GjerdrumSammendrag
With wood, the moisture content is an intrinsic volatile property - constantly changing in accordance to the environment. For the efficient use of timber, knowledge about the MC is increasingly being requested, and the sawmill being required to reveal such information. This paper presents an algorithm for estimating, on a weekly basis, the running MC and MC variation of a timber lot. Input variables are the MC of the lot when leaving the kiln, storage condition and running weather observations. The model, described in mathematical terms, is valid for timber stored on stickers, i.e. under homogeneous air circulation, and meant for implementation in the sawmill’s MPS.
Sammendrag
When conifers such as Picea abies (Norway spruce) are attacked by insects or pathogens, they often produce increased quantities of terpenoid oleoresin. This response can be mimicked in young P. abies seedlings by treatment with methyl jasmonate. In this study, we determined the effect of methyl jasmonate on the terpenoids and other chemical defenses of mature P. abies, and investigated if this treatment protected trees against attack by the blue-stain fungus Ceratocystis polonica, the most important fungal associate of the bark beetle Ips typographus. Methyl jasmonate treatment induced the formation of traumatic resin ducts in the developing xylem, enhanced resin flow, and stimulated increased accumulation of monoterpenes, sesquiterpenes, and diterpene resin acids. However, almost no significant changes in terpene composition were detected. In addition, no changes in soluble phenolic content were observed. There was a very high variability both among and within clones in the timing and degree of response to methyl jasmonate. These chemical and anatomical changes were correlated with increased resistance to C. polonica, suggesting that terpenoid oleoresin may function in defense against this pathogen.
Sammendrag
Using information from a regional survey of vascular plants of 130 sites in western Norway, a selection of sites based on a heuristic iterative complementarity-based nature reserve selection procedure was performed. The results indicate that conservation of traditionally managed hay meadows is of major importance as they contributed 60.1% of all native species recorded; afforested grasslands (deciduous woodlands < 70 years old) contributed 26.8%, whereas artificially fertilized hay meadows and intensively cultivated grasslands taken together contributed 13.1% of the species. The species composition of the meadows was significantly nested. Thus, if you conserve the most species-rich meadows, you also conserve most of the species in the less species-rich meadows. Nestedness in meadows was significantly correlated with within-meadow habitat diversity and soil pH. The most species-rich meadows were traditional meadows, characterized by high habitat diversity and high soil pH. These meadows will support nearly all species including habitat specialists and regionally rare species, whilst artificially fertilized hay meadows only support the generalist subset, i.e. common species. Area was not significantly correlated with nestedness suggesting that it is more important to cover many habitats than to preserve large traditional meadows just because they are large.
Forfattere
Line Hoem Erlend Ystrøm HaartveitSammendrag
Major driving forces among companies in the forest products industry are mergers and acquisitions and narrowing the strategic focus to core competencies. The combined effect is that the mutual dependency in customer-supplier relationships increases, and that the share of the total value added provided by each actor decreases. Standard techniques for process mapping are intended as the first step in process improvement. Order processes, extending from identification of demand to fulfilment of demand, commonly cross company borders. The result is an increasing need for inter-company coordination to increase efficiency of material flows. This paper presents preliminary results from the mapping of the order process between a Norwegian retail chain and its major supplier of solid wood products. A model intended for supply chain mapping has been modified and applied to this particular case. One outcome of the mapping is that a detailed overview of the process can reveal simple solutions for process improvement, as individual actors rarely focus on optimising their combined process, but rather have an internal focus. The mapping also provides a basis for evaluation of existing performance measurements, and for development of new measurements with a focus on improving the actors’ combined order process.
Forfattere
Torbjørn OkstadSammendrag
Det er ikke registrert sammendrag
Sammendrag
The notion of an ecological damage has so far neither been given a proper theoretical nor a pragmatic or operational foundation. Yet one of the most widespread motivations for the scientific study of ecosystems is a “protectional” one by which an improved scientific understanding is sought in order to be able to prevent future ecological damages. We review the possibilities of valuating changes in the environment, in health or in ecosystems as a damage. The conceptual separation of potential from actual behaviour/structure is a prerequisite to any of them. The critical point here is the formal and empirical basis for the knowledge about these potentials. We contrast the dynamic systems theory approach derived in physics with an interactive computing approach recently developed in computer science. The former requires to distinguish facts and values and leads to notorious difficulties when applied at the ecosystem level. The latter and novel approach opens the possibility for a consistent definition of a damage at the ecosystem level whenever a tradition of (sustainable) utilization of such systems is available. The documentation, actualisation and dissemination of the tacit (expert) knowledge can be improved by the use of interactive simulations in which a virtual standard can defined by the respective experts themselves.
Forfattere
Erlend Ystrøm Haartveit R.A. Kozak T.C. ManessSammendrag
In this paper, we review the development of supply chain management (SCM) and identify a number of considerations for applying these techniques to the forest products industry. A review of the literature found that SCM initiatives were primarily customer focused, where a significant amount of market pull exists. However, the forest products industry is characterized by sales of commodity products with push marketing. Successful implementation of SCM in these types of supply chains were found to focus on efficiencies through: 1) increasing throughput and 2) reducing inventories. Potential for efficiency improvements are larger when a holistic perspective is applied, integrating processes across companies in the supply chain. Two supply chain mapping methods were identified from the literature as key techniques for use in the forest products industry, and these were applied to three case companies in the western Canadian province of British Columbia. In general, it was found to be especially challenging to apply these techniques (and SCM in general) to commodity-based supply chains because of uncertainty in raw material supply, the relatively long lead times in production, and production processes that generate a relatively high percentage of consequence products. However, the mapping processes yielded some promising results with respect to creating an overview of supply chain structures, time consumption, and inventories. One major benefit derived from applying these methods would be improved communications between actors, customers, and suppliers along the supply chain. The authors suggest that SCM mapping tools be modified to improve their performance in analyzing supply chains for the forest products industry.
Forfattere
Peder GjerdrumSammendrag
EMC is traditionally analysed using small, clear wood specimens. However, some discrepancy was observed in full-size boards in a sawmill. In this experiment specimens of varying length from 10 to 120 mm clear wood and from 120 to 900 mm natural quality were tested. Commercial spruce boards were used. After kiln drying and proper conditionning, the samples were kept in a constant climate (40 °C, 65% RH) for half a year, until apparent equilibrium was reached. The EMC was observed by the dry weight method separately for adsorption and desorption. The EMC (average for ad- and desorption) was found to increase proportionally to the natural logarithm of the specimen length. Further, clear wood showed sifgnificantly higher EMC than natural quality. While for desorption the EMC was hardly influenced by length, desorption was highly length dependent. The difference in EMC (desorption) between a full-length board and a 10-mm clear specimen was estimated to 0.013 (fraction of dry wood). Accordingly, the hysteresis A:D ratio decreased from 0.96 for the shortest specimens to 0.88 for the longest. The results verify and extend earlier findings and are important for understanding and estimating the wood-moisture interaction of kiln dried timber, particulary for high drying quality specifications. However, the difficulty of deciding the EMC for large specimens should not be underestimated.
Sammendrag
Utvalgt Forelesning/Selected Talk: Survival and competitive successes of boreal forest trees depend on a balance between exploiting the full growing season and minimising frost injury through proper timing of hardening in autumn and dehardening in spring. Our research has shown that the female parents of Norway spruce adjust these timing events in their progeny according to the prevailing temperature conditions during sexual reproduction. Reproduction in a cold environment advances bud-set and cold acclimation in the autumn and dehardening and flushing in spring, whereas a warm reproductive environment delays these progeny traits by an unknown non-Mendelian mechanism. We have performed identical crosses in combination with timed temperature treatments during shorter and longer periods from female meiosis, pollen tube growth, syngamy and embryogenesis, tested the progenies for bud-set and frost hardiness, and concluded that the effect of temperature most likely is a response to accumulated heat during embryogenesis and seed maturation. Our first attempt to look for a molecular mechanism has revealed that transcription of PHYO, PHYP and PHYN and the class IV chitinase PaChi4 (using RealTime PCR) all show higher transcription levels in progenies born under cold conditions than their full-sibs born under warmer conditions. This result is consistent with preliminary findings that methylation of cytosine in total DNA is higher in progenies reproduce under warm conditions than their colder full-sib counterparts. If these observations are related to methylation, we may explain why progenies with a memory of a past time cold embryogenesis are more sensitive to short days than their full-sibs with a warmer embryonic history.
Sammendrag
We estimated time from death to fall (standing time) of Norway spruce (Picea abies (L.) Karst.) snags in a submountainous old-growth forest in south-central Norway, applying four calculation methods to 124 dendrochronologically cross-dated still-standing snags and 64 fallen logs. The calculation methods consistently estimated expected standing time of snags at 26–34 years, with a median of 16–21 years and 20% of snags standing for >48–58 years. The survival function from all methods took the approximate form of a negative exponential, with a 3%–4% annual fall rate for snags. In the distribution of time since death, a small peak in dead trees 20–30 years ago (late 1970s) coincides with a historic epidemic of bark beetles. The method using only time since death of still-standing snags appears to be the most feasible for estimating total standing time of snags in old-growth forests with constant tree mortality.