Effects of Climatic Stress on Red Deer Browse. Development of bilberry after an extreme weather event during the winter of 2014

De tørre og varme værforholdene med mye vind langs kysten på Vestlandet og i Trøndelag vinteren 2014 førte til en kraftig uttørking av en del plantearter, og det ble observert store områder med inntørka og død vegetasjon. Uttørkingen omfattet spesielt arter med vintergrønne blader (tyttebær), samt løvfellende planter der den overjordiske stengelen er levende (blåbær, og røsslyng). Slike fenomen omtales gjerne som klimastress og viser at planter i nordlige områder kan være sårbare for ekstreme værhendelser, spesielt høye temperaturer vinterstid. Blåbær er ei viktig plante for mange arter, fra store beitedyr til små insekter, og er en basisplante i mange næringskjeder. Endringer i blåbærlyngens biomassse kan derfor ha konsekvenser for mange andre arter..

Effekter av klimastress på hjortens vinterbeiter. Utvikling av blåbærlyngen etter tørkevinteren 2014

De tørre og varme værforholdene med mye vind langs kysten på Vestlandet og i Trøndelag vinteren 2014 førte til en kraftig uttørking av en del plantearter, og det ble observert store områder med inntørka og død vegetasjon. Uttørkingen omfattet spesielt arter med vintergrønne blader (tyttebær), samt løvfellende planter der den overjordiske stengelen er levende (blåbær, og røsslyng). Slike fenomen omtales gjerne som klimastress og viser at planter i nordlige områder kan være sårbare for ekstreme værhendelser, spesielt høye temperaturer vinterstid. Blåbær er ei viktig plante for mange arter, fra store beitedyr til små insekter, og er en basisplante i mange næringskjeder. Endringer i blåbærlyngens biomassse kan derfor ha konsekvenser for mange andre arter..

Airborne laser scanning reveals increased growth and complexity of boreal forest canopies across a network of ungulate exclosures in Norway

Large herbivores are often classed as ecosystem engineers, and when they become scarce or overabundant, this can alter ecosystem states and influence climate forcing potentials. This realization has spurred a call to integrate large herbivores in earth system models. However, we lack a good understanding of their net effects on climate forcing, including carbon and energy exchange. A possible solution to this lies in harmonizing data across the myriad of large herbivore exclosure experiments around the world. This is challenging due to differences in experimental designs and field protocols. We used airborne laser scanning (ALS) to describe the effect of herbivore removal across 43 young boreal forest stands in Norway and found that exclusion caused the canopy height to increase from 1.7 0.2 to 2.5 0.2 m (means SE), and also causing a marked increase in vertical complexity and above-ground biomass. We then go on to discuss some of the issues with using ALS; we propose ALS as an approach for studying the effects of multiple large herbivore exclosure experiments simultaneously, and producing area-based estimates on canopy structure and forest biomass in a cheap, efficient, standardized and reproducible way. We suggest that this is a vital next step towards generating biome-wide predictions for the effects of large herbivores on forest ecosystem structure which can both inform both local management goals and earth system models biomass, herbivory, large herbivores, LiDAR, moose, remote sensingpublishedVersio

Wind and Fisheries: Desktop Study on the Coexistence Between Offshore Wind and Fisheries in Sothern North Sea II

The Norwegian Government has launched a major initiative to promote offshore wind power , in which bottom-fixed wind power will be developed in the Southern North Sea II (SN II) area. There is a low level of fishing activities in this area with varying catch sizes over the years. The activities consist nearly exclusively of bottom trawling of sandeel. The fishing industry has raised concerns about the development of offshore wind farms (OWFs), including risks for collision and hindrance for fishing vessels, negative impacts on fish stocks, and other ecosystem-wide effects. This report has conducted a data study and compiled existing literature on these topics to, based on best available science, assess how OWF development could affect fisheries in SN II, the possibilities for facilitating coexistence for these two industries, and potential synergies. While the development of OWFs in SN II has the potential to bring both positive and negative effects on the fisheries as well as the marine life in the area, the findings suggest that coexistence between the two industries is possible. Potential impacts, including noise, magnetic fields, turbidity, artificial reef and FAD effects, and no-fishing zones, have not been shown to adversely affect populations of commercially important fish at OWF developments in the North Sea. With the ongoing technology shift to larger turbines, the space between each turbine is increasing, which may reduce collision risk. Seafloor cables can also be sufficiently buried to reduce the risk of damage by demersal trawls. Furthermore, most types of passive fishing gear (except for drifting nets) and practices are less problematic to use in an OWF. Should, though, the construction of OWFs in SN II cause restrictions on the fishery activities in the area, it is likely to cause increased fishing in other areas, often referred to in the scientific literature as the displacement effect, indicating that the economic loss will be smaller than the estimated catch values. Notable knowledge gaps are regarding positive and negative long term cumulative impacts and regional effects, impact on primary production and carbon assimilation from changed upper ocean mixing and impact from floating wind farms (not relevant in SN II). We emphasise the importance of early and ongoing input from relevant stakeholders to address concerns and find optimal mitigation measures for minimising the OWF footprint in SN II during the different phases of OWF development.Wind and Fisheries: Desktop Study on the Coexistence Between Offshore Wind and Fisheries in Sothern North Sea IIpublishedVersio

Functional traits of alpine plant communities show long-term resistance to changing herbivore densities

Herbivores shape vegetation by suppressing certain plant species while benefitting others. By thus modifying plant species functional composition, herbivores affect carbon cycling, albedo, vegetation structure and species' interactions. These effects have been suggested to be able to counteract the effects of increasing temperatures on vegetation in alpine environments. Managing the dominant large ungulates in these ecosystems could thus provide a tool to mitigate climate change effects. However, it is possible that legacy effects of past grazing will dampen ungulate impacts on vegetation. We shed a light on this topic by investigating the short- and long-term effects of varying sheep densities on the plant trait composition in the Norwegian alpine tundra with centuries-long of intensive grazing history. In the first part of our study, we quantified the effects of sheep on the plant community functional trait composition at different elevations and under moderate and low productivity in. We combined data from two long-term (14 and 19 yr) sheep fence experiments and showed that differences in sheep densities did not affect plant trait composition, irrespective of productivity. However, in the second part of our study, we showed that the plant trait composition in mainland (that has been grazed for centuries) differed from vegetation on islands which have been herbivore-free. Taken together, these results suggest that sheep have an effect on the alpine plant communities on historical time scales covering centuries, but that the resulting sheep grazing resistant/tolerant communities may not respond to shorter-term (14 and 19 yr) changes in sheep densities, that is, at temporal scales relevant for ecosystem management. Furthermore, we showed that the plant trait composition at the site with low productivity had gone through a temporal trait change independent of sheep treatment, potentially due to increased temperatures and precipitation, suggesting that sheep may not be able to counteract climatic impacts in the areas with centuries-long grazing history.publishedVersio

Mapping and Estimating Aboveground Biomass in an Alpine Treeline Ecotone under Model-Based Inference

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Natural and cultural heritage in mountain landscapes: towards an integrated valuation

Mountain areas of Europe have been managed by humans for a long time, leading to a prevalence of semi-natural habitats in mountain landscapes today. These landscapes contain both natural and cultural heritage; however, natural and cultural heritage are rarely considered together when valuing landscapes and developing management plans in protected areas. Here we present a case study of seven protected areas in the mountains of Great Britain and Norway. We take a long-term perspective on landscape and land-use change and propose an integrated model of landscape valuation on the basis of combined natural and cultural heritage. Our model plots indicators of natural and cultural heritage along a gradient of land-use intensity, allowing simultaneous assessment and highlighting how valuation depends on what type of heritage is considered. We show that while contemporary land-use changes follow similar trajectories in Norway and Britain, different land-use histories mean that the loss of heritage differs between the regions. The model presented here thus allows for the consolidation of valuation based on both cultural and natural heritage in landscapes.publishedVersio

Assessment of the risk to Norwegian biodiversity from import and keeping of American bison, European bison, domesticated water buffalo and domesticated yak.Scientific Opinion of the Panel on Alien Organisms and Trade in Endangered Species of the Norwegian Scientific Committee for Food and Environment

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Assessment of the risk to Norwegian biodiversity from import and keeping of American bison, European bison, domesticated water buffalo and domesticated yak. Scientific Opinion of the panel on Alien Organisms and Trade in Endangered Species (CITES) of the Norwegian Scientific Committee for Food and Environment

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Airborne laser scanning reveals uniform responses of forest structure to moose (Alces alces) across the boreal forest biome

1. The moose Alces alces is the largest herbivore in the boreal forest biome, where it can have dramatic impacts on ecosystem structure and dynamics. Despite the importance of the boreal forest biome in global carbon cycling, the impacts of moose have only been studied in disparate regional exclosure experiments, leading to calls for common analyses across a biome-wide network of moose exclosures. 2. In this study, we use airborne laser scanning (ALS) to analyse forest canopy re-sponses to moose across 100 paired exclosure-control experimental plots dis-tributed across the boreal biome, including sites in the United States (Isle Royale), Canada (Quebec, Newfoundland), Norway, Sweden and Finland. 3. We test the hypotheses that canopy height, vertical complexity and above- ground biomass (AGB) are all reduced by moose and that the impacts vary with moose density, productivity, temperature and pulse disturbances such as logging and insect outbreaks. 4. We find a surprising convergence in forest canopy response to moose. Moose had negative impacts on canopy height, complexity and AGB as expected. The responses of canopy complexity and AGB were consistent across regions and did not vary along environmental gradients. The difference in canopy height be-tween exclosures and open plots was on average 6 cm per year since the start of exclosure treatment (±2.1 SD). This rate increased with temperature, but only when moose density was high. 5. The difference in AGB between moose exclosures and open plots was 0.306 Mg ha−1 year−1 (±0.079). In browsed plots, stand AGB was 32% of that in the exclosures, a difference of 2.09 Mg ha−1. The uniform response allows scaling of the estimate to a biome-wide impact of moose of the loss of 448 (±115) Tg per year, or 224 Tg of carbon. 6. Synthesis: Analysis of ALS data from distributed exclosure experiments identified a largely uniform response of forest canopies to moose across regions, facilitat-ing scaling of moose impacts across the whole biome. This is an important step towards incorporating the effect of the largest boreal herbivore on the carbon cycling of one of the world's largest terrestrial biomes.publishedVersio