Nygaard P.H.,Norwegian Institute of Bioeconomy Research |
Oyen B.-H.,Coastal Forestry
Forests | Year: 2017
Positive and negative effects on ecosystem services from plantation forestry in Europe have led to conflicts regarding non-native tree species. Sitka spruce (Picea sitchensis (Bong.) Carr.) is the most common plantation species in northwest Europe, covering 1.3 Mha. In costal Norway, Sitka spruce was intentionally introduced and is currently occupying about 50,000 ha. Sitka spruce was blacklisted in Norway in 2012, mainly based on the risk for invasive spreading, but little quantitative documentation exists on spread. Here we quantify spread from plantations into abandoned heathland and pastures in thirteen sites where natural regeneration occurs. Spread distances and zero-square distributions related to the nearest edge of the parent stand were fitted by use ofWeibull. The median expansion rate was 0.8 m·year-1 in north Norway and 4.4 m·year-1 in west Norway. The maximum establishment distance measured was 996 m. A peak in sapling density occurred within 50 m from the edge, and there was a general decrease in saplings with increasing distance. Conversely, increase in zero-squares percentages occurred with increasing distance. We argue that inclusion of abundance in assessing spread is necessary to define invasiveness. Based on spread models and prevailing forestry practices we recommend that the establishment of new Sitka spruce plantations within 200 m of protected areas should be avoided. © 2017 by the authors.
Sonsteby A.,Norwegian Institute of Bioeconomy Research |
Heide O.M.,Norwegian University of Life Sciences
Journal of Horticultural Science and Biotechnology | Year: 2017
Plants of six strawberry cultivars were raised under controlled conditions and tested for flowering and yield potential. Short days (SD) at intermediate temperatures for 4 weeks in August induced profuse flowering in subsequent long days (LD) in all cultivars except the late-flowering ‘Malwina’. LD conditions induced flowering only in ‘Nobel’, which has an everbearing parent. ‘Nobel’ and ‘Saga’ exhibited broad temperature adaptation for SD floral induction, which was generally reduced or suppressed at 9 and 27°C. After autumn planting, all cultivars flowered most abundantly in plants raised in SD and intermediate temperatures. Flowering was earliest in ‘Nobel’ and ‘Rumba’. Plants that did not reach floral commitment after 4 weeks in SD continued and completed induction under subsequent natural SD conditions after planting in the field, demonstrating the capability of fractional induction. Berry yield varied in parallel with flowering in the field and was always higher in plants raised under SD conditions. The traditional cultivars ‘Florence’ and ‘Sonata’ out-yielded the more recent cultivars. Some cultivars lost more than two thirds of their initiated flowers during the winter with obvious consequences for their yields. With proper raising management, acceptable yields were obtained after autumn planting even in a cool Nordic climate. © 2017 The Journal of Horticultural Science & Biotechnology Trust
Lindblom L.,University of Bergen |
Blom H.H.,Norwegian Institute of Bioeconomy Research
Lindbergia | Year: 2016
For almost twenty years Xanthoria calcicola was considered extinct on bark in Sweden. Here, we report X. calcicola growing on bark at 14 localities in Skåne, southernmost Sweden. In total, ca 300 thalli were observed on bark, and the populations vary from 1 to 200 thalli. In all localities except one X. calcicola was also present and more abundant on neighboring substrates made of stone, such as churchyard walls, church walls or tombstones. Preliminary results from fungal ITS data reveal that haplotypes found on bark are always present in the surrounding wall populations. We conclude that trees are suboptimal habitats for X. calcicola and only colonized when in close vicinity of an established wall population. The most obvious threat to epiphytic X. calcicola is the cutting down of host trees. © 2016 The Authors.
Treu A.,Norwegian Institute of Bioeconomy Research |
Zimmer K.,Norwegian Institute of Bioeconomy Research
International Wood Products Journal | Year: 2017
Creosote is commonly used as a wood preservative for highway timber bridges in Norway. However, excessive creosote bleeding at various highway timber bridge sites lead to complaints, and a potentially bad reputation for wooden timber bridges. Macro-and micro-anatomical factors such as the amount of heartwood, annual ring width, annual ring orientation, ray-height and composition and resin canal area were investigated in order to classify seven timber bridges in Norway into bleeding- and non-bleeding bridges. A classification into bleeding and non-bleeding was possible for discriminant categories based on three anatomical factors analysed on wood core samples. The amount of heartwood content dominated the influencing factors, even obscuring the significance of other factors. Classification with a low amount of variables was done preferably on sample level instead of bridge level, due to the restricted number of 17 core samples per bridge. © 2017 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group
Aune-Lundberg L.,Norwegian Institute of Bioeconomy Research |
Strand G.-H.,P.O. Box 115 As
Norsk Geografisk Tidsskrift | Year: 2017
Detailed descriptions of individual vegetation types shown on vegetation maps can improve the ways in which the composition and spatial structure within the types are understood. The authors therefore examined dwarf shrub heath, a vegetation type covering large areas and found in many parts of the Norwegian mountains. They used data from point samples obtained in a wall-to-wall area frame survey. The point sampling method provided data that gave a good understanding of the composition and structure of the vegetation type, but also revealed a difference between variation within the vegetation type itself (intra-class variation) and variation resulting from the inclusion of other types of vegetation inside the map polygons (landscape variation). Intra-class variation reflected differences in the botanical composition of the vegetation type itself, whereas landscape variation represented differences in the land-cover composition of the broader landscape in which the vegetation type was found. Both types of variation were related to environmental gradients. The authors conclude that integrated point sampling method is an efficient way to achieve increased understanding of the content of a vegetation map and can be implemented as a supporting activity during a survey. © 2017 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.
Heltoft P.,Norwegian Institute of Bioeconomy Research |
Wold A.-B.,Norwegian University of Life Sciences |
Molteberg E.L.,Norwegian Institute of Bioeconomy Research
Postharvest Biology and Technology | Year: 2017
Important factors for development of quality defects are the physical, physiological and chemical state of the tubers, which is also described as the maturity status of the crop. The use of maturity indicators as predictors of quality in potato tubers during and after storage was explored in cvs. Asterix and Saturna with three different maturity levels during three years (2010, 2012 and 2013). The maturity indicators measured 1–3 weeks before harvest and at harvest included haulm senescence (haulm maturity), skin set (physical maturity), dry matter content (physiological maturity) and contents of sucrose, glucose and fructose (chemical maturity). Potato quality parameters were measured three times during storage (December, February and April) and included dry matter content, sucrose, glucose and fructose contents, weight loss and fry colour. Cultivar and maturity level were included as categorical predictors in a linear regression model and contributed significantly (P < 0.001) to the models predicting reducing sugars during storage. Dry matter, sucrose, glucose and fructose were included as continuous predictors in the linear regression models and contributed significantly (P < 0.01) to the sucrose, glucose and fructose models and these models explained a high proportion of the variation (R2 ≥ 0.88). Skin set contributed significantly to the weight loss models (P < 0.01) but the models showed low R2-values (R2 < 0.48). Sucrose contents contributed significantly (P = 0.05) to the fry colour model for Asterix and the fry colour models for both Asterix and Saturna had R2-values of 0.50 and 0.51 respectively. This study provides new information about the influence of maturity on potato quality during storage and the potential of using field measurements of maturity as predictors of storage potential for processing potato cultivars Asterix and Saturna in Norway. © 2017 Elsevier B.V.
News Article | March 1, 2017
Until the modern era, the human mark on the northernmost forests of North America, Europe, and Asia was light. Human populations in these challenging environments were too small to make a big impact through agriculture or timber harvests. But increasing evidence indicates people influenced the northern forests indirectly, by igniting or suppressing fires. Distinguishing human from climatic influence on historical fire patterns is critical to forest management planning, which is guided by historical patterns of fire frequency, size, and intensity. A boreal forest nature reserve in southern Norway offered a unique opportunity to reconstruct past events, as scientists from the Norwegian Institute of Bioeconomy Research (NIBIO) demonstrated in a report published online ahead of print in the Ecological Society of America's journal Ecological Monographs. The trees told a story of a surge in human-instigated fires during the 17th and 18th centuries, followed by fire suppression after AD 1800, as economic motivations changed. Unlike the boreal forests of North America, which more frequently experience fires hot enough to kill most trees, the forests of Norway, Sweden, and Finland characteristically burn at low to medium intensity. Fires burn through the understory, leaving mature trees scarred, but living. The burn scars, combined with tree ring data, and historical documents, present a record of wildfire behavior in the second millennium. Together with former PhD-student Ylva-li Blanck of the Norwegian University of Life Science, researchers Jørund Rolstad and Ken Olaf Storaunet collected and analyzed 459 wood samples from old, fire-damaged pine tree stumps, snags, downed logs and living trees in 74 square kilometers (28 square miles) study area in Trillemarka-Rollagsfjell nature reserve. At 60 degrees North, Trillemarka-Rollagsfjell shares a latitude close to Anchorage, Alaska and Whitehorse, the capital of Canada's Yukon province. The pine and spruce dominated forest ecosystem has many traits in common with the forested ecosystems of interior Alaska and Canada. The collected samples were cross-dated by dendrochronology, a method used to date wooden samples by comparing tree rings with a known time-sequence from many other collected and dated tree ring series. In this way, scientists can determine the date and location of forest fires with great accuracy. Based on where in the tree ring the damage occurred, the forest researchers can also say at what time of the year it burned. From this record, the authors estimated fire location, frequency, size, and seasonality over the last 700 years, comparing the fire history to historical records from the National Archives of Norway, including juridical documents, diplomas, and old maps of the area and old agricultural textbooks and reports. They dated 254 individual fires from AD 1257-2009. The oldest living tree they sampled dated to AD 1515 and the oldest stump to AD 1070. From AD 1300 to 1600, wildfires ignited during late summer, with about 5-10 ignitions per quarter century, generally occurring during warm, dry summers. In the next two centuries, fire frequency rose dramatically, particularly in the mid-17th century. Early summer fires grew in prevalence. Books and other documents from this time period record a rising use of slash-and-burn cultivation and rangeland burning, explained author Ken Olaf Storaunet. The population was recovering from the devastation of the Black Death and several subsequent epidemics. People returned to abandoned lands and began using fire to improve land for grazing animals and to cultivate crops. The average length of time between recurrences of fire in the same location fell by half, from 73 to 37 years. Increasing demand for timber in Europe raised the value of forests and discouraged slash-and-burn cultivation practices. The fires legislation banning the use of fire in Norway came in 1683. After AD 1800, fire frequency and size dropped precipitously, with only 19 fires occurring in the study area during the last 200 years. Ecologically, the period from 1625 and onwards to today is probably unique, and something that perhaps has not happened in thousands of years, Storaunet said. Studies in Alaska and Canada have projected that hotter, drier summers may increase annual wildfire burn areas by two to three times by the end of the century. In Norway, the North Atlantic Ocean may temper hotter summers with more precipitation. Forest fires can be catastrophic and damaging for both home owners and the forest industry. In Canada each year, on average, 8,600 fires burn 25,000 square kilometers (10,000 square miles) of forest. But forest fires play an important part in the ecology of northern forests. Natural forests are not a continuous expanse of old trees. Forest fires create a mosaic of burnt and unburnt areas, shaping the species composition and the age distribution of the forest. Fires open up the tree canopy, letting light in, releasing nutrients to the understory, and aiding regrowth. Charcoal changes soil structure, and charred tree trunks become habitats of great importance for the biological diversity of the forest--both above and below ground. Many rare species, especially fungi and insects, depend on the variation forest fires create. Many of today's forest reserves have perhaps never been as unnatural as they are today, Storaunet pointed out. The historical studies in Trillemarka-Rollagsfjell nature reserve show that fire has been a natural, and very dynamic, part of the forest ecosystem throughout history. And this ecosystem is affected by climate, vegetation and not least the way humans use forest, Storaunet said. Rolstad, J., Blanck, Y. and Storaunet, K. O. (2017), Fire history in a western Fennoscandian boreal forest as influenced by human land use and climate. Ecological Monographs (early view) doi:10.1002/ecm.1244. Open Access. The Ecological Society of America, founded in 1915, is the world's largest community of professional ecologists and a trusted source of ecological knowledge, committed to advancing the understanding of life on Earth. The 10,000 member Society publishes five journals and a membership bulletin and broadly shares ecological information through policy, media outreach, and education initiatives. The Society's Annual Meeting attracts 4,000 attendees and features the most recent advances in ecological science. Visit the ESA website at http://www. .
News Article | December 24, 2016
Terry Brown, owner of Brown's Tree Farm, welcomed me warmly into his modest farmhouse. We sat at the kitchen table in straight backed chairs, and looked out a large window at rows of fir trees outside, a red barn in the distance. The whole scene was awash in wispy, dry snow flurries. In the coming days and weeks, these trees would find themselves inside homes all over Chemung County, in Upstate New York. I had come to speak with him about the challenges of the Christmas tree business, and if he's concerned that it will get harder due to climate change. He recalled some of his greatest trials growing trees over the years. "A few years ago, I had this whole field—at least 2/3rds of it—full of Douglas fir. And they were beautiful. Then a virus came through—it was called," he paused a moment to retrieve the name from memory, "the Swiss needle cast—and it wiped em right out." And in his first year planting—some 40 years ago—he lost 4,000 trees in a drought. But while he's concerned about climate change on the whole, as a farmer, he's experienced see-saw weather patterns firsthand his whole life and is not entirely sure that it's going to impact the tree growing business anytime soon. "Things have definitely changed, you know, worldwide, and I understand the science of it, but as a lifelong farmer you always bounce back and say well 'jeepers, I've seen this before.' My dad is 94 and he's seen it all before." Christmas trees cover a wide spectrum of evergreens, with different species grown and sold in different regions of the US and world. Fir trees, like Balsam and Fraser fir, are the most popular here in the United States because of their soft needles and lush growth. Christmas trees are grown in almost every state in the nation with major centers of production in North Carolina, the Northeast, the Great Lakes region, and the Pacific Northwest. Despite competition from artificial look-a-likes (Most of which are produced in the Pearl River Delta region in China), Americans still love their all-natural trees. In 2015, 29.5 million trees worth $1.32 billion found their way into American households. How the Christmas tree industry as a whole is going to be affected by climate change is unclear, but individual tree species and the farmers growing them are going to be affected in myriad ways that are likely to cause some amount of disruption. Hotter and drier conditions are something most Christmas tree species will have to contend with all around the US. Whether these conditions change what types of species are grown and sold will depend on how severe they get, but it's not hard to imagine some tree types getting taken out of the equation. "Some can take it and some can't," said Brown. Dendrologist Donald Leopold, of the State University of Environmental Science and Forestry in Upstate New York explained to me via email that some evergreens like Scotch pine are able to withstand hotter conditions because of special features like thicker, waxier needles and deeper root systems that help them retain moisture. These types of conifers might make easier Christmas trees to grow in the future. "Fraser and balsam fir will always have a big fan club, but if they can't be grown as abundantly in the US due to climate change," he said. "Their price will likely increase and some people will simply not be able to afford them." If it gets particularly balmy in, say, the South, where a high percentage of Fraser firs are grown, Leopold surmised that "species rarely grown now, like Turkish fir, will become more common as this and other species are better adapted to warmer and drier conditions." A rising temperature also brings other, gnawing consequences to conifer trees: insect pests. "Most likely climate change will favor insects and diseases more than trees," said entomologist Paal Krokene, of the Norwegian Institute of Bioeconomy Research, in Norway. Selling Christmas trees is ultimately a cosmetic industry, and rampaging bark beetles and sapsuckers that deform trees are bad for business. Slight malformations on a tree usually mean the scrap pile. "Christmas tree farmers don't tolerate much damage to their trees," he said. Jeff Owen, a Forestry Specialist from North Carolina State University, told me that farmers have been dealing with seasonal inconsistencies like drought and flood for as long as they can remember, and that they're masters at problem solving. But the thing that concerns him is shifting seasons that could make trees vulnerable. Taking a break from trimming Fraser firs to chat on the phone, he said "If we've had a really mild fall, growers get nervous and will delay harvest as long as they can to make sure the trees have had a chance to go dormant." Dormancy is a kind of tree hibernation. If trees aren't dormant when they're harvested, they can die. On the other side of winter, if early spring is particularly mild, "the trees can start trying to break bud one to two weeks earlier," said Owen. But he warned: "if you have the trees starting to grow too soon and then you get a hard freeze, you can lose that new growth. That's one of those things that is very hard for a grower to deal with." At his kitchen table, Terry Brown expressed a similar sentiment with me. "What is it going to do to the seasons?" he said, referring to climate change, his arms crossed. "If in April the weather is all of a sudden like June, that changes everything." If the tree industry is to be hit hard by climate change in the future, that's how, he thought. "Timing is everything in this business." Because of climate change, the most popular Christmas tree types could switch out for other hardier species—trading out some of the firs for more spruces, say. Perhaps live trees will even reach a price that causes some staunch real-tree-consumers to go against their morals and buy artificial trees (nothing says happy holidays like genuine PVC). Or maybe farmers will find a way, like they have so many times before, to overcome the challenges ahead and keep growing the species they've got. Brown leaned forward in his chair and folded his hands upon the table, eyes looking out at the rows of Christmas trees outside. "One thing I do notice is our summers—the heat," he said. "There is a lot of heat in that sun. I think more so than I can remember." Clearing his throat slightly, he added "I trim all of these trees by hand, and while I'm not as young as I used to be, I'm just not able to do as many in a day as I used to, because it's hotter than hell." "It's a wait and see," he said.
Hoffman M.,Cornell University |
Flo B.E.,Norwegian Institute of Bioeconomy Research
Journal of Environmental Policy and Planning | Year: 2016
In a landscape of fragmented private ownership, the need to coordinate game management across large areas presents challenges for landowners and public agencies alike. This paper describes how a recent reorganization of moose management in Norway achieves landscape-level planning while maintaining a tradition of local management by hunting teams. These two seemingly contradictory imperatives – coordinating wildlife management across large areas while keeping benefits and control in the hands of local resource users – are resolved through a nesting of management institutions, wherein the state serves a regulatory function and mid-level government (the county) serves to facilitate inter-local cooperation. This paper documents how the system is structured and describes the balance of incentives that enable the system to work. Information was gathered via interviews with staff at the Norwegian Directorate for Nature Management (now called the Norwegian Environment Agency), with wildlife management officials at the municipal level, with hunters, and from the most recent regulatory documents. © 2016 Informa UK Limited, trading as Taylor & Francis Group
Refsgaard K.,Norwegian Institute of Bioeconomy Research |
Bechmann M.,Norwegian Institute of Bioeconomy Research
Journal of Environmental Planning and Management | Year: 2016
In this paper, we estimate the cost-effectiveness of tillage methods as a measure to reduce phosphorus loss. The study was based on real-world information on costs. Data on phosphorus loss for different soil tillage methods were modelled. The cost-effectiveness of various soil tillage methods were related to autumn ploughing. The results showed large variation in cost-effectiveness related to erosion risk. Furthermore, spring harrowing was the most cost-effective method to reduce phosphorus loss, followed by autumn harrowing and spring ploughing in spring cereals. Implementation of changed tillage methods showed lower costs for spring cereals compared to winter wheat. The differences in costs between areas were most evident for spring tillage due to differences in yields and agronomic management. Cost-effectiveness is an important criterion in selecting mitigation methods, but due to large variations in the effect of changed tillage, these should be locally adapted to the high risk areas of erosion. © 2016 University of Newcastle upon Tyne