NINA Brage (Norsk institutt for naturforskning)
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Stay or go? Changing breeding conditions affect sexual difference in colony attendance strategies of Atlantic puffins Fratercula arctica
Get PDFMale and female birds have different roles in reproduction and, thereby in their reproductive investment, which in turn may increase negative effects of poorer breeding conditions caused by e.g., climate change or ecosystem regime shifts. By using a 33-year time series of resightings of Atlantic puffins Fratercula arctica individually colour-ringed as breeders in previous years, we showed that the difference in colony attendance of male and female birds depended on the environmental conditions for raising young, proxied by the average duration of the chick period and size of the herring Clupea harengus fed to the chicks in the colony each year. The longer the chick period, the more was the sex ratio of adults sitting visibly in the colony biased in favour of males. An increase in herring size, indicating better feeding conditions for raising chicks, led to more observations of both sexes. Additionally, we found that birds were observed less with age and females more so than males. We discuss the results in relation to general life-history theory on sexual differences in trade-offs between individual investment in breeding and own survival. Our results suggest that females are increasingly more willing than males to invest in provisioning for the chick the more and longer the chick needs such care.publishedVersio
Effects on biodiversity in semi-natural pastures of giving the grazing animals access to additional nutrient sources: a systematic review
Get PDFBackground Traditionally managed semi-natural pastures are recognised for their high biodiversity. One drawback is that these pastures are often low in fodder production and hence rather unprofitable, which may lead to abandonment. Two ways to increase production and profitability and maintain grazing are to (i) offer the grazers supplementary feed, or (ii) co-enclose the semi-natural pasture with an improved pasture. Both practices may transfer nutrients to the semi-natural pasture, with potential negative effects on biodiversity. This systematic review aimed to analyse the available evidence concerning the following primary question: “What is the effect of giving grazers access to additional nutrient sources on biodiversity in semi-natural pastures?” (Q1). We also used two supporting questions: “What is the effect of giving grazers access to additional nutrient sources on nutrient status of the soils of semi-natural pastures?” (Q2) and “How do the grazers of semi-natural pastures behave while having access to additional nutrient sources?” (Q3). Methods Searches for peer-reviewed and grey literature were made using bibliographic databases, search engines, specialist websites, and stakeholder contacts. Literature was screened for relevance according to predefined eligibility criteria, and critical appraisal was performed using the tool CEECAT. A database of the relevant studies was compiled. Descriptive information about the evidence base is presented in tables and an interactive evidence atlas. Because of absent study setup replication, Q1 and Q2 were not analysed quantitatively. However, sample size allowed the use of mixed modelling to quantitatively analyse Q3 regarding the effects of (i) co-enclosing an improved pasture on grazers’ electivity for the improved area, and (ii) supplementary feed on the forage intake of grazers. Review findings A total of 12 articles on the effects of supplementary feeding and 19 on the effects of co-enclosing an improved pasture were included, of which some targeted multiple review questions. Because of the limited literature, it is not possible to draw any conclusions concerning the effects on biodiversity (Q1) or nutritional status (Q2) in semi-natural pastures. For Q3, 28 studies fulfilled our criteria, of which 18 investigated the behaviour of grazers related to co-enclosing an improved pasture, and 10 investigated their forage intake while having access to supplementary fodder. The results show that all grazer species except goats preferred grazing in the improved areas regardless of whether they were grazing together with other grazer species or not. We found no effect of supplementary feeding on forage intake of the grazers. Conclusions We detected a knowledge gap concerning the effects of the two additional nutrient sources on semi-natural pasture biodiversity (Q1) and nutrient status (Q2), which points toward further research needs. Analysis of Q3 showed that grazers prefer to graze improved compared to semi-natural pasture areas. However, how this behaviour subsequently affects nutrient transport and biodiversity is unclear and cannot be translated into management recommendations. To gain better knowledge about the primary question of our review, research focusing specifically on this question is needed. We provide suggestions for how such studies could be designed, including spatio-temporal setup, and key management and environmental conditions to consider. Conservation, Grazing management, Nutrient addition, Plant species richness, Sustainable farmingpublishedVersio
An overview of kelt migration in regulated rivers: status, knowledge gaps, and future directions toward safe downstream passage at hydropower facilities
Get PDFAtlantic salmon (Salmo salar), brown trout (Salmo trutta), and steelhead trout (Oncorhynchus mykiss) kelts have important conservation value for population resilience. Nonetheless, relative to other salmonid life-stages, knowledge on their behavior and survival is poor. This is especially true for kelt downstream migration in rivers fragmented by hydropower plants (HPP), even though the physiological and survival consequences are severe when functional connectivity is not provided. Here, the existing information about kelt downstream migration past HPP was summarized, beginning with an overview of iteroparous salmonid lifecycles. Then, the importance of kelts for conservation and the threats they encounter while migrating was discussed. Finally, the current corpus of peer-reviewed literature and reports focused on kelt migration in these systems was presented. Kelt studies have focused on five main themes: (1) postspawning survival, (2) migration delays before dam passage, (3) passage selection and guidance efficiency, (4) passage mortality, and (5) the swimming behaviors of kelts during migration. Overall, there was a paucity of information about kelts and several information gaps and needs for future research. This work should inform scientists and river managers on the conservation of salmonids in regulated rivers, including the development of passage solutions for safe downstream migration.Hydropower, dams, migration barriers, fish passage, SalmonidpublishedVersio
Fra granplantefelt til stedegen fjellbjørkeskog i Junkerdalsura naturreservat: korttidseffekter av restaurering på vegetasjon
Get PDFIn the forests of Europe, the planting of spruce in deciduous forests has had a significant impact on forest
ecosystems. Junkerdalsura nature reserve north of Saltfjellet in Nordland has large areas covered by species rich mountain birch forests. A threat to these native birch forests is the spread of Norway spruce Picea abies, which was planted in parts of the reserve between the 1920s and 1960s. Restoration measures were therefore initiated to restore the native mountain birch forest with associated vegetation. Logging with timber extraction was carried out in two spruce plantations in 2018 and 2019. In 2022, we investigated the effect of these measures on the vegetation. We found that partial logging in an area with some remaining canopy cover of birch Betula pubescens and spring water influence, resulted in a species composition and cover of species in the field layer equivalent to the surrounding birch forest already three years after the restoration measure. More extensive logging in a somewhat drier area resulted in an increase of pioneer species mainly dominated by raspberry Rubus idaeus four years after the restoration measure. Although species richness did not reach the level of the birch forest in any of the areas, the results show that restoring species composition in birch forest can be fast if conditions are right. Logging intensity, remaining canopy cover and spring water influence can be important factors affecting the recovery process after restoration in boreal mountain birch forests. This study in Junkerdalsura is the only known study of restoration of boreal mountain birch forests in the Nordic countries and is an important contribution to the knowledge of restoration of these forests.publishedVersio
The value of hyperspectral UAV imagery in characterizing tundra vegetation
No full textThe fine-scale spatial heterogeneity of low-growth Arctic tundra landscapes necessitates the use of high- spatialresolution remote sensing data for accurate detection of vegetation patterns. While multispectral satellite and aerial imaging, including the use of uncrewed aerial vehicles (UAVs), are common approaches, hyperspectral UAV imaging has not been thoroughly explored in these ecosystems. Here, we assess the added value of hyperspectral UAV imaging relative to multispectral UAV imaging in modelling plant communities in low-growth oroarctic tundra heaths in Saariselk¨ a, northern Finland. We compare three different spectral compositions: 4- channel broadband aerial images, 5-channel broadband UAV images and 112-channel narrowband UAV images. Based on field vegetation plot data, we estimate vascular plant aboveground biomass, leaf area index, species richness, Shannon’s diversity index, and community composition. We use spectral and topographic information to compile 12 explanatory datasets for random forest regression and classification. For aboveground biomass and leaf area index, the highest R2 values were 0.60 and 0.65, respectively, and broadband variables were most important. In the best models for biodiversity metrics species richness and Shannon’s index R2 values were 0.53 and 0.46, respectively, with hyperspectral, topographic, and multispectral variables having high importance. For 4 floristically determined community clusters, both random forest classifications and fuzzy cluster membership regressions were conducted. Overall accuracy (OA) for classification was 0.67 at best, while cluster membership was estimated with an R2 of 0.29–0.53. Variable importance was heavily dependent on community composition, but topographic, multispectral, and hyperspectral data were all selected for these community composition models. Hyperspectral models generally outperformed multispectral ones when topographic data were excluded. With topographic data, this difference was diminished, and performance improvements from added hyperspectral data were limited to 0–10 percentage point increases in R2 , the largest occurring in the metrics with lowest R2 . These results suggest that while hyperspectral can outperform multispectral imaging, multispectral and topographic data are mostly sufficient in practical applications in tundra heaths. Tundra Plant communities Multispectral imaging Hyperspectral imaging Drone BiodiversitypublishedVersio
Shifting from techno-economic to socio-ecological priorities: Incorporating landscape preferences and ecosystem services into the siting of renewable energy infrastructure
Get PDFThis study examines the siting scenarios for renewable energy installations (REI) in a mountainous region of Europe (Switzerland), incorporating the external costs of ecosystem services and, innovatively, social preferences. This approach challenges the prevalent techno-economic siting paradigm, which often overlooks these externalities. To minimize the external costs of the scenarios while maximizing energy yield, Marxan, an optimization software, was employed. The energy target for all scenarios is set at 25 TWh/a, stemming from the energy gap anticipated due to the phase-out of Swiss nuclear reactors by 2050. This target is met using renewable energy infrastructure such as wind, roof-mounted photovoltaic, and ground-mounted photovoltaic systems. By integrating social preferences into the optimization, this study showcases a promising implementation that transcends the software’s intended applications. It complements techno-economic approaches and offers alternative decision-making avenues. The conventional "roof first" strategy proved ineffective in preventing extensive land use for the development of new renewable energy infrastructure. Strategies incorporating ground-mounted photovoltaic infrastructure were more spatially, ecologically, and socially efficient than those without. The strategy optimized for energy yield exhibited the highest spatial efficiency but incurred significant ecosystem service costs and, surprisingly, had low social costs. In contrast, the strategy prioritizing ecosystem services was the most efficient in terms of ecosystem service costs but had elevated social costs and was spatially less efficient than other strategies. The strategy optimized for social preferences incurred the lowest social costs and excelled in spatial efficiency and ecosystem service costs. Notably, this strategy employed a limited number of planning units linked to both high ecosystem service and social costs. The findings underscore that incorporating social preferences significantly enhances the evaluation of siting options. This inclusion allows for the social acceptance of investments to be factored into costs, facilitating more informed and inclusive decisions.Shifting from techno-economic to socio-ecological priorities: Incorporating landscape preferences and ecosystem services into the siting of renewable energy infrastructurepublishedVersio
Drivers of species composition in arable-weed communities of the Austrian–Hungarian borderland region: What is the role of the country?
Get PDFQuestions: Due to their high ecological and agronomical variability, borderland re -gions offer an excellent opportunity to study assembly patterns. In this study we compared the influence of various factors on summer annual weed communities con -sisting of both native and introduced species. Location: The borderland region of Austria and Hungary. Methods: We assessed the abundance of weed species in 300 fields of six summer annual crops, and collected information on 26 background variables for each plot. We applied redundancy analysis (RDA) to estimate multivariate species responses and variation partitioning to compare the relative importance of three groups of variables (environmental variables, management variables, and country as a singleton group), and we also checked for statistical association between country and the predictors of the other two groups. Results: The full RDA model explained 22.02% of the variance in weed species com -position. Variation partitioning showed that environment and management had simi-larly high (~8%) influence on weeds, while country had a modest yet substantial (~1%) effect, and there was relatively little overlap between the variance attributable to the three groups. Comparing the individual variables, country ranked third (after preced-ing crop, and actual crop). The effects of 15 further variables were also significant, in -cluding seven management, and seven environmental variables, as well as the location of the sampling plots within the fields. Comparisons between the countries showed that farming type, preceding crops, tillage system, tillage depth and field size were significantly different between the countries. Conclusions: Country exhibited a small but significant influence on weed commu-nity composition, which could not be explained with easily accessible management and environmental variables. This suggests that the distinct historical agronomical background of the two countries, possibly involving some legacies of the former Iron Curtain period, still has an impact on the weed species composition of arable fields. agriculture, annual crops, arable weeds, climate, country effect, ecological legacy, Iron Curtain, variance partitioning, weed survey, weed vegetationpublishedVersio
Silvicultural regime shapes understory functional structure in European forests
Get PDF1. Managing forests to sustain their diversity and functioning is a major challenge in a changing world. Despite the key role of understory vegetation in driving forest biodiversity, regeneration and functioning, few studies address the functional dimensions of understory vegetation response to silvicultural management. 2. We assessed the influence of the silvicultural regimes on the functional diversity and redundancy of European forest understory. We gathered vascular plant abundance data from more than 2000 plots in European forests, each associated with one out of the five most widespread silvicultural regimes. We used generalized linear mixed models to assess the effect of different silvicultural regimes on understory functional diversity (Rao's quadratic entropy) and functional redundancy, while accounting for climate and soil conditions, and explored the reciprocal relationship between three diversity components (functional diversity, redundancy and dominance) across silvicultural regimes through a ternary diversity diagram. 3. Intensive silvicultural regimes are associated with a decrease in functional diversity and an increase in functional redundancy, compared with unmanaged conditions. This means that although intensive management may buffer communities' functions against species or functional losses, it also limits the range of understory response to environmental changes. 4. Policy implications. Different silvicultural regimes influence different facets of understory functional features. While unmanaged forests can be used as a reference to design silvicultural practices in compliance with biodiversity conservation targets, different silvicultural options should be balanced at landscape scale to sustain the multiple forest functions that human societies are increasingly demanding. ecosystem resilience, forest understory, functional diversity, functional redundancy, silvicultural regime, sustainable forest management, unmanaged forestspublishedVersio
Green transformation or green colonialism – contrasting perspectives on how to address the climate and nature crisis
Get PDFFormålet med denne artikkelen er å identifisere hvordan ulike perspektiver som kommer til uttrykk i debatten om det grønne skiftet kan forstås og begrunnes i Norge og Sverige, med særlig fokus på arealbruk, basert på offisielle uttalelser i offentlige dokumenter og uttalelser og meninger i media. Det antas at disse perspektivene kan knyttes til grunnleggende verdier som for eksempel antroposentrisme eller økosentrisme. Gitt at ulike perspektiver på arealbruk kan identifiseres, identifiserer artikkelen også hvilke typer politiske virkemidler som ifølge litteraturen har potensial til å bygge bro mellom de ulike perspektivene. Litteraturen anerkjenner både tradisjonelle politiske virkemidler (regulatoriske, økonomiske og informative), inkludert fysisk planlegging, men foreslår også at man bør teste ut mer innovative virkemidler innen både økonomiske insentiver og informasjonsbaserte og frivillige virkemidler for å dempe arealbrukskonflikter i forbindelse med det grønne skiftet.The aim of this paper is to, based on official statements in public documents as well as statements and opinions in media, identify how different perspectives that appear in the debate about the green transformation can be understood and justified in Norway and Sweden with a specific focus on land use. It is assumed that these perspectives can be linked to fundamental values such as for example anthropocentrism or ecocentrism. Given that different perspectives on land use can be identified, the paper also identify what type of policy instruments the literature suggests has a potential to bridge the different perspectives. The literature acknowledges traditional policy instruments (regulatory, economic and informative) including spatial planning, but also suggest testing more innovative policy instruments within the realm of economic incentives, information, and voluntary instruments, to mitigate land use conflicts in the context of green transformation
Bird migration at Lista and Utsira 2023. Migration for Development
Get PDFCordes, L.S., Hamre, Ø., Nilsson, A.L.K., López, A., Portelo, D., Røer, J.E. & May, R. 2024. Bird migration at Lista and Utsira 2023. NINA Report 2483. Norwegian Institute for Nature Research.
The Migration for Development project is jointly funded by industry partners and implemented to complement and support the VisAviS collaborative research project funded by the Research Council of Norway. As part of the work, two avian radars were deployed at coastal locations in Norway to record seasonal bird migrations. Here, we present an investigation of the avian radar data collected at Lista (Farsund municipality) during the spring and autumn and at Utsira during the autumn of 2023. Firstly, using radar tracks annotated by an observer, we show case issues with how the radar classifies bird tracks (small, medium, large and flock). We used the data from annotated tracks to provide improved categories of radar tracks. Secondly, using all tracks collected by the radar, we filtered these based on likely migration flight characteristics, and present temporal and spatial patterns of probable migration tracks.
The length and definition of the migration season varied by location. Migration peaks most consistently occurred from late afternoon through the evening. There were significant site- and season-specific differences in flight height and the proportion of birds in the rotor swept zone. At Lista a significant proportion of birds flew within the clearance zone between the sea surface and the rotor swept zone. We recommend including the proportion of birds flying in this narrow band (20m) in considerations of impacts of wind energy developments. Birds tended to migrate with a tail or cross-tail wind. Lastly, there were site-specific differences in size groups detected at Lista and Utsira, with Utsira predominantly detecting birds in the intermediate category and just a few large flocks, but no small birds. At Lista, all categories were detected by the radar.Cordes, L.S., Hamre, Ø., Nilsson, A.L.K., López, A., Portelo, D., Røer, J.E. & May, R. 2024. Fugletrekk på Lista og Utsira 2023. NINA Rapport 2483. Norsk institutt for naturforskning.
Migrasjon for utvikling-prosjektet er fellesfinansiert av industripartnere og er igangsatt for å komplementere og støtte VisAviS samarbeidsprosjekt finansiert av Norges forskningsråd. Som en del av arbeidet ble to fugleradarer utplassert på kystlokasjoner i Norge for å registrere sesongbaserte fugletrekk. Her presenterer vi en undersøkelse av fugleradardata samlet inn på Lista (Farsund kommune) i løpet av våren og høsten, og på Utsira i løpet av høsten i 2023. For det første, ved å bruke radarspor annotert av en observatør, viser vi problemer med hvordan radaren klassifiserer fuglespor (små, mellomstore, store og flokker). Vi brukte data fra annoterte spor for å gi forbedrede kategorier av radarspor. For det andre, ved å bruke alle spor samlet inn av radaren, filtrerte vi disse basert på sannsynlige trekkflygningskarakteristikker og presenterer trekkmønstre i tid og rom av sannsynlige trekkspor.
Lengden og avgrensningen av trekkperioden varierte etter lokasjon. Trekktopper oppsto mest konsistent fra sen ettermiddag til kveld. Det var betydelige sted- og sesongspesifikke forskjeller i flygehøyde og andelen fugler som beveget seg i samme høyde som rotor sveipsonen på et vindkraftverk. På Lista fløy en betydelig andel av fuglene innenfor sonen mellom havoverflaten og rotor sveipsonen. Vi anbefaler å inkludere andelen av fugler som flyr i dette smale båndet (20m) i vurderinger rundt virkninger av vindkraftutvikling. Fugler hadde en tendens til å migrere i medvind eller delvis medvind. Til slutt var det stedsspesifikke forskjeller i størrelsesgrupper oppdaget på Lista og Utsira, hvor Utsira hovedsakelig detekterte fugler i mellomkategorien og bare noen få store flokker, men ingen små fugler. På Lista ble alle kategorier detektert av radaren.Norwegian Water Resources and Energy Directorate (NVE), Norwegian Environment Agency, Equinor, RWE Renewables Norway, Hafslund Vekst, Fred Olsen Seawind, Ørsted Ventures Norway, Vårgrønn, Marin Energi Testsenter (NOWC), Offshore Norge, Mainstream RP, TotalEnergies EP, Deep Wind Offshor