Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2012
Authors
Jihong Liu ClarkeAbstract
No abstract has been registered
Authors
Jihong Liu ClarkeAbstract
No abstract has been registered
Authors
Jihong Liu ClarkeAbstract
No abstract has been registered
Authors
Jihong Liu ClarkeAbstract
No abstract has been registered
Authors
Inge Stupak Brian Titus Nicholas Clarke Tat Smith Andis Lazdins Iveta Varnagiryte-Kabasinskiene Kestutis Armolaitis Milica Peric Claudia GuidiAbstract
No abstract has been registered
Abstract
This study examines already existing guidelines for the sustainable removal of slash from forests for bioenergy use. Existing guidelines from some countries, states and provinces with forest ecosystems comparable to Norways (Sweden, Finland, the U.K., Ireland, Minnesota, New Hampshire and British Columbia) are compared with the Norwegian Living Forests (LF) and Debio (ecological forestry) guidelines. The aim is to identify areas where the Norwegian guidelines could be further developed.
Authors
Nicholas ClarkeAbstract
No abstract has been registered
Authors
Nicholas ClarkeAbstract
This report aims to summarise briefly the findings in the scientific literature concerning the effect of both stem-only and whole-tree harvesting on soil carbon stocks. Although the findings reported by previous authors vary, it is possible to draw some general conclusions about the effect of harvesting on soil carbon, and on whether whole-tree harvesting has a greater effect than stem-only harvesting. In general it appears that the organic C content in the soil’s organic layer is reduced after stem-only harvesting, sometimes by as much as 50%. This reduction has been explained in several ways. After a period of maybe 20 years, the carbon content of the organic layer starts to increase again. In the mineral soil a reduction is not always apparent and the C content can even increase, probably because of the incorporation of residues into the soil. Some studies have shown that this increase is short-lived, while others have found a longer-term increase. Unsurprisingly, thinning appears to affect the soil carbon content much less than clear-cutting; the effect tends to be proportional to the thinning intensity. The soil carbon content appears to be higher after selection cutting than after clear-cutting. Studies comparing effects of whole-tree harvest with those of stem-only harvest have tended to show smaller carbon contents in the mineral soil after whole-tree harvest than after stem-only harvest, although once again results vary greatly. There are many factors affecting soil C content and thus accounting for the observed differences, including temperature, moisture content, and harvesting type. Variation in the results obtained may depend on site-specific factors such as site nutrient status, especially with regard to the most common limiting nutrient nitrogen, which will affect growth in the next rotation. Making sure there are enough nutrients available, if necessary by compensatory fertilisation, will improve carbon sequestration in both trees and soil.
Authors
Nicholas ClarkeAbstract
This report presents preliminary results from investigations on changes in soil water chemistry after stem-only and whole-tree harvesting at a site in eastern Norway, with emphasis on major nutrients, pH and dissolved organic carbon. For stem-only harvesting (SOH) and whole-tree harvesting where slash had been piled (WTH pile), concentrations of nitrate, calcium, magnesium, and potassium peaked in the second year after harvesting and again, but lower, in the third. Ammonium concentrations peaked in the year after harvesting. There was slight acidification after harvesting. No increased concentrations of dissolved organic carbon were observed. In general, trends were similar between SOH and WTH piles, compared to where slash had been removed to form the piles. Peaks in concentrations were higher for WTH piles compared to SOH. The results agree well with results from other field measurements reported in the scientific literature.
Authors
M Ashraful Islam Goutam Kuwar Jihong Liu Clarke Dag-Ragnar Blystad Hans Ragnar Gislerød Jorunn Elisabeth Olsen Sissel TorreAbstract
Abstract Strict control of morphogenesis is essential in production of potted poinsettia. Commonly, this is obtained by the use of plant growth retardants (PGRs), often in combination with early morning temperature drops. Due to negative effects on human health and the environment, the use of PGRs is becoming restricted. Also, energy-saving growth regimes and periods of high temperatures limit effective use of temperature drops. In the present study the use of a high proportion of blue (B) light provided by light emitting diodes [LEDs, 20% blue (B), 80% red (R)] was compared with traditional high pressure sodium (HPS) lamps (5% B) providing similar phytochrome photostationary state to produce compact poinsettia plants. Both in the greenhouse and growth chamber, all cultivars were 20–34% shorter for LED compared to HPS grown plants. Also, leaf and bract area as well as chlorophyll content and total dry matter accumulation were lower under LED. The LED did not delay bract color formation, visible cyathia and flowering compared to HPS, and no difference in post production performance (cyathia/bract abscission or necrosis) between the two light treatments was found. The effect of end of day-red (EOD-R) lighting combination with LED and HPS supplemental lamps during the photoperiod in the greenhouse was also investigated. Reduced stem extension (13%) was observed under HPS only and for one of the two cultivars tested, whereas under the LED regime, there was no effect of EOD-R lighting.