NINA Brage (Norsk institutt for naturforskning)
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Modifying and parameterizing the individual-based model inSTREAM for Atlantic salmon and brown trout in the regulated Gullspång River, Sweden
Get PDFWe modified, parameterized, and applied the individual-based model inSTREAM version 6.1 for lake-migrating populations of landlocked Atlantic salmon (Salmo salar) and brown trout (S. trutta) in a residual flow stretch of the hydropower-regulated Gullspång River, Sweden. This model description is structured according to the TRACE model description framework. Our aim was to model responses in salmonid recruitment to alternative scenarios of flow release and other environmental alterations. The main response variable was the number of large out-migrating juvenile fish per year, with the assumption that individuals are more inclined to out-migrate the larger they get, and that migration is an obligatory strategy. Population and species-specific parameters were set based on local electrofishing surveys, redd surveys, physical habitat surveys, broodstock data as well as scientific literature. • Simulations were set to run over 10 years, with sub-daily time steps, in this spatially and temporally explicit model. • Model calibration and validation of fish growth was done using data on juvenile fish from electrofishing. • The results were found to be sensitive to parameter values for aggregated fish, i.e., “superindividuals” and for the high temperature limit to spawning. Ecohydraulics Conservation Ecological modelling Water Framework Directive Salmo salar Salmo trutta Environmental flow Minimum flow Natural flow regime Habitat selectionpublishedVersio
Low-intensive agricultural landscapes could help to sustain Green Peafowl Pavo muticus inhabiting surrounding forest patches in Northern Thailand
Get PDFWildlife in Southeast Asia is greatly affected by agricultural expansion. While intensive farming
causes biodiversity decline, low-intensive farming can support some adapted wildlife. In
Thailand, the rapid transformation of forests to agricultural landscapes over three decades has
resulted in large forest and biodiversity loss, with several Endangered species suffering from
cropland expansion. Among these, the Green Peafowl, an Endangered Galliformes widely
distributed across Southeast Asia, has shown the capacity to adapt well to low-intensive agri culture landscapes by using crops as food sources. Here we investigated in detail the Green
Peafowl’s habitat use in an agricultural landscape surrounding a large forest patch composed of
three protected areas in northern Thailand. Using line transect surveys and compositional anal ysis, we estimated the monthly Peafowl use of different crop types and different crop structures
between January 2020 and January 2021. The Green Peafowl’s habitat use was significantly non random. The order of habitat preference was timber plantations > orchards > cropland > fallow
land. The species also preferred cropland within a 500 m buffer zone around the forest patch. The
species preferred crops with a canopy structure (timber and orchards) that resembles their natural
habitat. Our results confirm that low-intensive and diversified agricultural landscapes could help
to sustain the Green Peafowl population. Importantly, we also show that closed canopy crops,
such as large tree plantations like teak, rubber and orchards, can provide good alternatives for
reforestation to reconnect forest fragments and isolated patches in highly degraded habitats as
they allow the species to move further away from forest edges within the degraded landscape.publishedVersio
The cost of research: Lasting effects of capture, surgery and muscle biopsy on brown bear (Ursus arctos) movement and physiology
Get PDFAnimal models are a key component of translational medicine, helping transfer scientific findings into practical applications for human health. A fundamental principle of research ethics involves weighing the benefits of the research to society against the burden imposed on the animals used for scientific purposes. The utilisation of wild animals for research requires evaluation of the effects of capture and invasive sampling. Determining the severity and duration of these interventions on the animal’s physiology and behaviour allows for refining study methodology and for excluding or accounting for biased data. In this study, 39 Scandinavian brown bears (Ursus arctos) captured either while hibernating in winter or via helicopter in summer and that underwent surgery as part of a human health project had their movement, body temperature and timing of onset of hibernation compared with those of 14 control bears that had not been captured during the same period. Bears captured in winter and summer showed decreased movement from den exit until late summer, compared to those in the control group. Bears captured in summer showed reduced movement and body temperature for at least, respectively, 14 and 3 days, with an 11% decrease in hourly distance, compared to pre-capture levels, but did not differ in the timing of hibernation onset. We reveal that brown bear behaviour and physiology can be altered in response to capture and surgery for days to months, postcapture. This has broad implications for the conclusions of wildlife studies that rely upon invasive sampling. animal welfare; body temperature; capture effects; ecophysiology; hibernation; movementpublishedVersio
Behaviour of anadromous brown trout (Salmo trutta) in a hydropower regulated freshwater system
Get PDFMany Norwegian rivers and lakes are regulated for hydropower, which afects freshwater ecosystems and anadromous fish species, such as sea trout (Salmo trutta). Lakes are an important feature of many anadromous river systems. However, there is limited knowledge on the importance of lakes as habitat for sea trout and how hydropower afects the behaviour of sea trout in lakes. To investigate this, we conducted an acoustic telemetry study. A total of 31 adult sea trout (532±93 mm total length) were captured by angling in river Aurlandselva, Norway, and tagged between July 20 and August 12, 2021. The tags were instrumented with accelerometer, temperature, and depth sensors, which provided information on the sea trout’s presence and behaviour in lake Vassbygdevatnet. Our results indicate that there was a large prevalence of sea trout in the lake during the spawning migration, and that the sea trout were less active in the lake compared to the riverine habitats. An increase in activity of sea trout in the lake during autumn might indicate that sea trout spawn in the lake. However, the discharge from the high-head storage plant into the lake did not afect the depth use or activity of sea trout in the lake. Furthermore, the large prevalence of spawners in the lake during autumn will likely cause an underestimation of the size of the sea trout population in rivers with lakes during annual stock assessment. In conclusion, our results could not fnd evidence of a large impact of the discharge on the behaviour of sea trout in the lake. Biologging, Anadromous brown trout, Hydropower, Lake ecology, AccelerationpublishedVersio
Mapping density, diversity and species-richness of the Amazon tree flora
Get PDFUsing 2.046 botanically-inventoried tree plots across the largest tropical forest on Earth, we
mapped tree species-diversity and tree species-richness at 0.1-degree resolution, and
investigated drivers for diversity and richness. Using only location, stratified by forest type, as
predictor, our spatial model, to the best of our knowledge, provides the most accurate map of
tree diversity in Amazonia to date, explaining approximately 70% of the tree diversity and
species-richness. Large soil-forest combinations determine a significant percentage of the
variation in tree species-richness and tree alpha-diversity in Amazonian forest-plots. We
suggest that the size and fragmentation of these systems drive their large-scale diversity
patterns and hence local diversity. A model not using location but cumulative water deficit,
tree density, and temperature seasonality explains 47% of the tree species-richness in the
terra-firme forest in Amazonia. Over large areas across Amazonia, residuals of this relationship
are small and poorly spatially structured, suggesting that much of the residual
variation may be local. The Guyana Shield area has consistently negative residuals, showing
that this area has lower tree species-richness than expected by our models. We provide
extensive plot meta-data, including tree density, tree alpha-diversity and tree speciesrichness
results and gridded maps at 0.1-degree resolution.publishedVersio
Forest science between human and nonhuman agency
Get PDFThis paper explores the distribution of agency in forest science. Studies of forest science tend to view it primarily as seeking to control and exploit natural resources. But recent turns in social theory open for understandings of human-nature relations beyond human control. This paper explores what such insights can mean for the understanding of forest science. It asks how nonhumans and nonhumans interact in practices of forest science and together constitute certain forms of agency. How are the activities engaged in by students and lecturers affected by nonhumans? How do they respond to nonhumans? The empirical scope of this paper focuses interaction between students and lecturers at bachelor’s level. Fieldwork was carried out in June 2023 by joining students and lecturers on excursions. In-depth interviews with eleven students were also conducted. The paper observes how students and lecturers actively distanced themselves from the forest science of the past for ignoring the requirements of trees and the services of their surrounding environments. Indeed, lecturers repeatedly addressed preferences and performances of nonhuman beings. This had major implications for which decisions were available. The paper therefore suggests that nonhumans and humans interacted in numerous ways. Students and lecturers responded to trees, wildlife, soil, and climate. Nonhumans especially affected decisions related to logging and planting, thereby providing inescapable premises for the actions of forest science practitioners, and ultimately contributing to both enable and constrain agency. To conclude, the paper discusses a few limitations and implications of its findings. Forest science Forestry Nonhuman agency Biodiversity Climate change SoilpublishedVersio
Wealth of nomads – an exploratory analysis of livestock inequality in the Saami reindeer husbandry
Get PDFThe evolution of political complexity is a perennial issue in humanities and social sciences. While social inequality is pervasive in contemporary human societies, there is a view that livestock, as the primary source of wealth, limits the development of inequalities, making pastoralism unable to support complex or hierarchical organisations. Thus, complex nomadic pastoral organisation is predominantly caused by external factors: historically, nomadic political organisations mirrored the neighbouring sedentary population’s sophistication. Using governmental statistics from 2001 to 2018 on reindeer herding in Norway, this study demonstrates that there is nothing apparent in pastoral adaptation with livestock as the main base of wealth that levels wealth inequalities and limits social differentiation. This study found that inequality generally decreased in terms of the Gini coefficient and cumulative wealth. For example, the proportion owned by the wealthy decreased from 2001 to 2018, whereas the proportion owned by the poor increased. Nevertheless, rank differences persisted over time with minor changes. In particular, being poor is stable; around 50% of households ranked as poor in 2001 continued to be so in 2018. In summary, the results of this study indicate that pastoral wealth inequality follows the same pattern as all forms of wealth. Wealth accumulates over time, and while the highest earners can save much of their income (i.e., newborn livestock), low earners cannot. Thus, high-earners can accumulate more wealth over time, leading to considerable wealth inequality.Wealth of nomads – an exploratory analysis of livestock inequality in the Saami reindeer husbandrypublishedVersio
Testing UAV surveying for mapping freshwater pearl mussel populations
Get PDFThis report presents a preliminary assessment of the viability of using UAVs (drones) for mapping freshwater pearl mussel (Margaritifera margaritifera; FPM) populations. The standard methods for surveying FPM populations – wading or snorkelling through a river and counting the visible adult FPMs on the riverbed – are time-consuming and therefore costly. In contrast, UAVs offer the potential to quickly and efficiently map large stretches of a watercourse at high spatial resolution. Since UAVs have not been used as part of FPM monitoring programmes, an assessment of the strengths and limitations of this technology is required. In the current study, the effectiveness of UAVs to survey adult FPM populations was tested in the River Borråselva, a small, regulated river in Trøndelag, Central Norway, with a well-documented FPM population. Sites with known occurrence of FPMs were selected and a UAV, flying at an elevation of ≈5 m, was used to image the riverbed. UAV imagery was acquired using both photo and video surveying approaches. Photos were merged in WebODM to create orthophotos of the sites; video data were used to test the potential for image processing to remove phenomena that hindered discernment of FPMs (e.g. sunglint, shallow water wave lensing, and refraction from ripples). UAV flights were carried out under different light conditions, and in different sections of the river, to explore possible influences on FPM visibility. The test surveys showed that it is possible to provide a relatively quick indication of FPM distributions. However, two limitations were encountered. First, the area that could be investigated within a single survey for the Borråselva was limited by the difficulty of flying a UAV close to the surface within a narrow stream bounded by fully grown riparian forest, while maintaining line-of-sight to the operator. Secondly, detection of FPMs was strongly dependent on light conditions. We conclude that UAVs have strong potential for use in FPM monitoring programmes. However, careful survey planning is essential to ensure optimal surveying conditions: surveys should only be done during bright, cloud-free weather conditions, and attempts should be made to minimize the presence of shadows and sunglint. Additionally, image processing may be necessary to increase the visibility of FPMs on the riverbed.Hedger, R.D., Gosselin, M.-P. & Larsen, B.M. 2023. Testing av UAV-undersøkelser for kartlegging av elvemuslingpopulasjoner. NINA Rapport 2353. Norsk institutt for naturforskning.
Denne rapporten presenterer en foreløpig vurdering av UAV-er (droner) som verktøy for å kartlegge bestander av elvemusling (Margaritifera margaritifera; FPM). Standardmetodene for å kartlegge bestander av elvemusling – vading eller snorkling i en elv og telling av synlige elvemuslinger på elvebunnen – er både tidkrevende og kostbare. I motsetning til dette, tilbyr UAV-er potensialet for å kartlegge effektivt store deler av et vassdrag med høy romlig oppløsning. UAV-er har imidlertid ikke blitt brukt som en del av overvåkingsprogrammer av elvemuslingbestander eller testet for dette før, slik at det i denne sammenhengen kreves en vurdering av både styrker og begrensninger av denne teknologien. I denne studien ble effektiviteten til UAV-er for å kartlegge bestander av elvemuslinger testet i Borråselva, en liten, regulert elv i Trøndelag, Midt-Norge, med en godt dokumentert bestand av elvemusling. Steder med god forekomst av elve muslinger ble valgt og en UAV, som fløy i en høyde på ≈5 m, ble brukt til å avbilde elvebunnen. UAV-bilder ble anskaffet ved å bruke både foto- og videomålingsmetoder. Bilder ble slått sammen i WebODM for å lage ortofoto av kartlagte områder; videodata ble brukt for å teste potensialet for bildebehandling for å fjerne forstyrrende elementer i bildet (f.eks. reflekser fra sola, bølgelinjer på grunt vann og brytning fra krusninger). UAV-flyvninger ble utført under forskjellige lysforhold, og i forskjellige deler av elven, for å utforske mulig påvirkninger på synlighet av elvemuslinger. Testundersøkelsene viser at det er mulig å gi en relativt rask indikasjon på utbredelsen av elvemusling. Imidlertid ble det funnet to viktige begrensninger. For det første, var området som kunne undersøkes i Borråselva, innenfor en enkelt flyvning, begrenset pga. problemer med å fly en UAV nær overflaten av elva, som hadde fullvokst kantskog langs elvebredden, og samtidig opprettholde siktlinje til operatøren. For det andre, var resultatene sterkt avhengig av lysforholdene under undersøkelsen. Det ble konkludert med at UAV-er har et godt potensial for bruk i undersøkelser og overvåking av elvemusling. God planlegging er imidlertid avgjørende for å sikre optimale undersøkelsesforhold. Undersøkelser bør gjøres under lyse, skyfrie værforhold, samtidig er det viktig å minimere tilstedeværelsen av skygger og reflekser fra sola. I tillegg kan bildebehandling være nødvendig for å øke synligheten til elvemuslinger på elvebunnen
The role of non-English-language science in informing national biodiversity assessments
Get PDFConsulting the best available evidence is key to successful conservation decision-making. While much scientific evidence on conservation continues to be published in non-English languages, a poor understanding of how non-English-language science contributes to conservation decision-making is causing global assessments and studies to practically ignore non-English-language literature. By investigating the use of scientific literature in biodiversity assessment reports across 37 countries/territories, we have uncovered the established role of non-English-language literature as a major source of information locally. On average, non-English-language literature constituted 65% of the references cited, and these were recognized as relevant knowledge sources by 75% of report authors. This means that by ignoring non-English-language science, international assessments may overlook important information on local and/or regional biodiversity. Furthermore, a quarter of the authors acknowledged the struggles of understanding English-language literature. This points to the need to aid the use of English-language literature in domestic decision-making, for example, by providing non-English-language abstracts or improving and/or implementing machine translation.acceptedVersio
Simple Principles for Guiding of Large-Scale Landscape Restorations
Get PDFRestoration projects are complex and especially upscaling of restoration represent challenges that must be solved in a multidisciplinary setting. To establish cooperation between the wide range of professions there is a need for “fixed points” of communication that allows for constructive dialogue and to prevent misconceptions. We have developed and tested four simple principles that are aimed for use throughout the restoration process and to be immediately applicable for “on-the-ground” interventions. They are designed to work dynamically in the dialog between all personnel involved in a project, such as project owners, contractors, authorities, and consultants. By organizing the dialogue towards the four simple principles it is easier to explain the link between goals, specific work procedures and how they are solved. The principles can also be used when the projects are evaluated. The article focuses mainly on the use of the principles for nature diversity and landscapes, but they are also used and intended for all professions involved in restoration projects. Ecosystem Restoration; Project Principles; “Green Training”; Multidisciplinary Integration; Natural Processes; DialoguepublishedVersio