173 research outputs found

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

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    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

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    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..

    Effectiveness of conservation measures to support biodiversity in boreal timber-production forests

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    Large parts of the boreal forest ecosystems have been greatly affected by human use, and the current timber-oriented forest management practice that dominates boreal forests is proven to cause biodiversity and ecosystem services declines. These negative effects are mitigated in various ways, including in-situ measures implemented upon harvest. The measures comprise trade-offs between economic and ecological aims; thus, requiring solid knowledge of their effectiveness. However, comprehensive literature review of the effectiveness of such measures is scarce. We aim to fill part of this void by reviewing the scientific literature that have gauged effects of four in-situ conservation measures: green tree retention (GTR), patch retention (PR), dead wood retention (DW) and riparian buffer zones (RB). Two outcomes were considered, species richness and species abundance across taxa. From a total of 3012 initial papers, 48 met our inclusion criteria that generated 238 unique results. Results were grouped according to control. 178 studies used mature, unlogged forest as control. Out of those, 68% of the findings were not significant, i.e., suggesting no significant impact of harvest with biodiversity measures on species richness and species abundance compared to no harvest. Eighteen percent of the observations showed negative effects and 14% of the observations showed positive effects compared to no harvest. Sixty studies used harvest with no measures as control, of which 45% showed significant positive effects, meaning that compared to harvest with no measures, harvest with conservation measures has positively effects on species richness and abundance. However, 43% of the studies found no significant effect of the implemented conservation measures compared to harvest with no measures taken. The relatively few significant results reported restrain distinct conclusions on the effectiveness of the assessed conservation measures, but some degree of conservation measure is likely to have positive effects on biodiversity in timber-production forest. However, the scientific basis does not allow for pointing to threshold levels. Higher transparency of study design and statistical results would allow us to include more studies. There is a clear need for more research of effectiveness of common conservation measures in timber-production forests in order to strengthen the knowledge basis. In particular, there are few studies that employ harvest without any conservation measure as control. This is pivotal knowledge for forest managers as well as for policymakers for preserving biodiversity and the ecosystems in forest

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

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    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

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    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

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    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

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

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    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
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