Environmental Controls of InSAR-Based Periglacial Ground Dynamics in a Sub-Arctic Landscape

Periglacial environments are characterized by highly dynamic landscapes. Freezing and thawing lead to ground movement, associated with cryoturbation and solifluction. These processes are sensitive to climate change and variably distributed depending on multiple environmental factors. In this study, we used multi-geometry Sentinel-1 Synthetic Aperture Radar Interferometry (InSAR) to investigate the spatial distribution of the mean annual ground velocity in a mountainous landscape in Northern Norway. Statistical modeling was employed to examine how periglacial ground velocity is related to environmental variables characterizing the diverse climatic, geomorphic, hydrological and biological conditions within a 148 km(2) study area. Two-dimensional (2D) InSAR results document mean annual ground velocity up to 15 mm/yr. Vertical and horizontal velocity components in the East-West plane show variable spatial distribution, which can be explained by the characteristics of cryoturbation and solifluction operating differently over flat and sloping terrain. Statistical modeling shows that slope angle and mean annual air temperature variables are the most important environmental factors explaining the distribution of the horizontal and vertical components, respectively. Vegetation and snow cover also have a local influence, interpreted as indicators of the ground material and moisture conditions. The results show contrasted model performance depending on the velocity component used as a response variable. In general, our study highlights the potential of integrating radar remote sensing and statistical modeling to investigate mountainous regions and better understand the relations between environmental factors, periglacial processes and ground dynamics.Peer reviewe

Microclimate temperature variations from boreal forests to the tundra

Microclimate varies greatly over short horizontal and vertical distances, and timescales. This multi-level heterogeneity influences terrestrial biodiversity and ecosystem functions by determining the ambient environment where organisms live in. Fine-scale heterogeneity in microclimate temperatures is driven by local topography, land and water cover, snow, and soil characteristics. However, their relative influence over boreal and tundra biomes and in different seasons, has not been comprehensively quantified. Here, we aim to (1) quantify temperature variations measured at three heights: soil (-6 cm), near-surface (15 cm) and air (150 cm), and (2) determine the relative influence of the environmental variables in driving thermal variability. We measured temperature at 446 sites within seven focus areas covering large macroclimatic, topographic, and ecosystem gradients (tundra, mires, forests) of northern Europe. Our data, consisting of over 60 million temperature readings during the study period of 2019/11-2020/10, reveal substantial thermal variability within and across the focus areas. Near-surface temperatures in the tundra showed the greatest instantaneous differences within a given focus area (32.3 degrees C) while the corresponding differences for soil temperatures ranged from 10.0 degrees C (middle boreal forest) to 27.1 degrees C (tundra). Instantaneous differences in wintertime air temperatures were the largest in the tundra (up to 25.6 degrees C, median 4.2 degrees C), while in summer the differences were largest in the southern boreal forest (13.1 degrees C, median 4.8 degrees C). Statistical analyses indicate that monthly-aggregated temperature variations in boreal forests are closely linked to water bodies, wetlands, and canopy cover, whereas in the tundra, variation was linked to elevation, topographic solar radiation, and snow cover. The results provide new understanding on the magnitude of microclimate temperature variability and its seasonal drivers and will help to project local impacts of climate change on boreal forest and tundra ecosystems.Peer reviewe

Bioclimatic atlas of the terrestrial Arctic

The Arctic is the region on Earth that is warming at the fastest rate. In addition to rising means of temperature-related variables, Arctic ecosystems are affected by increasingly frequent extreme weather events causing disturbance to Arctic ecosystems. Here, we introduce a new dataset of bioclimatic indices relevant for investigating the changes of Arctic terrestrial ecosystems. The dataset, called ARCLIM, consists of several climate and event-type indices for the northern high-latitude land areas > 45°N. The indices are calculated from the hourly ERA5-Land reanalysis data for 1950–2021 in a spatial grid of 0.1 degree (~9 km) resolution. The indices are provided in three subsets: (1) the annual values during 1950–2021; (2) the average conditions for the 1991–2020 climatology; and (3) temporal trends over 1951–2021. The 72-year time series of various climate and event-type indices draws a comprehensive picture of the occurrence and recurrence of extreme weather events and climate variability of the changing Arctic bioclimate

Multiscale mapping of plant functional groups and plant traits in the High Arctic using field spectroscopy, UAV imagery and Sentinel-2A data

The Arctic is warming twice as fast as the rest of the planet, leading to rapid changes in species composition and plant functional trait variation. Landscape-level maps of vegetation composition and trait distributions are required to expand spatially-limited plot studies, overcome sampling biases associated with the most accessible research areas, and create baselines from which to monitor environmental change. Unmanned aerial vehicles (UAVs) have emerged as a low-cost method to generate high-resolution imagery and bridge the gap between fine-scale field studies and lower resolution satellite analyses. Here we used field spectroscopy data (400-2500 nm) and UAV multispectral imagery to test spectral methods of species identification and plant water and chemistry retrieval near Longyearbyen, Svalbard. Using the field spectroscopy data and Random Forest analysis, we were able to distinguish eight common High Arctic plant tundra species with 74% accuracy. Using partial least squares regression (PLSR), we were able to predict corresponding water, nitrogen, phosphorus and C:N values (r (2) = 0.61-0.88, RMSEmean = 12%-64%). We developed analogous models using UAV imagery (five bands: Blue, Green, Red, Red Edge and Near-Infrared) and scaled up the results across a 450 m long nutrient gradient located underneath a seabird colony. At the UAV level, we were able to map three plant functional groups (mosses, graminoids and dwarf shrubs) at 72% accuracy and generate maps of plant chemistry. Our maps show a clear marine-derived fertility gradient, mediated by geomorphology. We used the UAV results to explore two methods of upscaling plant water content to the wider landscape using Sentinel-2A imagery. Our results are pertinent for high resolution, low-cost mapping of the Arctic.Peer reviewe

Global maps of soil temperature

Research in global change ecology relies heavily on global climatic grids derived from estimates of air temperature in open areas at around 2 m above the ground. These climatic grids do not reflect conditions below vegetation canopies and near the ground surface, where critical ecosystem functions occur and most terrestrial species reside. Here, we provide global maps of soil temperature and bioclimatic variables at a 1-km(2) resolution for 0-5 and 5-15 cm soil depth. These maps were created by calculating the difference (i.e. offset) between in situ soil temperature measurements, based on time series from over 1200 1-km(2) pixels (summarized from 8519 unique temperature sensors) across all the world's major terrestrial biomes, and coarse-grained air temperature estimates from ERA5-Land (an atmospheric reanalysis by the European Centre for Medium-Range Weather Forecasts). We show that mean annual soil temperature differs markedly from the corresponding gridded air temperature, by up to 10 degrees C (mean = 3.0 +/- 2.1 degrees C), with substantial variation across biomes and seasons. Over the year, soils in cold and/or dry biomes are substantially warmer (+3.6 +/- 2.3 degrees C) than gridded air temperature, whereas soils in warm and humid environments are on average slightly cooler (-0.7 +/- 2.3 degrees C). The observed substantial and biome-specific offsets emphasize that the projected impacts of climate and climate change on near-surface biodiversity and ecosystem functioning are inaccurately assessed when air rather than soil temperature is used, especially in cold environments. The global soil-related bioclimatic variables provided here are an important step forward for any application in ecology and related disciplines. Nevertheless, we highlight the need to fill remaining geographic gaps by collecting more in situ measurements of microclimate conditions to further enhance the spatiotemporal resolution of global soil temperature products for ecological applications.Peer reviewe

Baltic herring as nutrition – Risk-benefit analysis

Tämän tutkimuksen tarkoitus oli selvittää, onko silakansyönnistä enemmän terveyshyötyä kuin -haittaa Suomessa ja millainen tilanne on eri ikäryhmissä. Aiemmat hyöty-riskiarviot ovat osoittaneet, että kalansyönti on yleensä terveellisempää kuin sen syömättä jättäminen. Tämä johtuu erityisesti kalan terveellisistä omega-3-rasvahapoista. Kuitenkin iso osa hyödyistä tulee aikuisille, joilla on suurentunut sydäntautiriski, ja osa mahdollisista haitoista tulee lapsille hammasvaurioiden ja muiden kehityshäiriöiden riskinä. Eviran toimeksiantona, yhteistyössä THL:n kanssa on vuoden 2014 aikana tehty hyöty-haitta-analyysi, jossa on tarkasteltu nimenomaan eri ikäryhmiä erikseen nykyisen kalankäytön mukaan. Tulokset perustuvat Taloustutkimuksen tekemän kyselyn aineistoon vuodelta 2013, jonka pohjalta on tehty varsinainen terveysvaikutusten tarkastelu. Tulokset ilmaistiin käyttäen haittapainotettuja elinvuosia (Disability Adjusted Life Year DALY) eli yksi DALY vastaa yhtä menetettyä tervettä elinvuotta. Hyödyllisistä ravintoaineista raportissa tarkasteltiin omega-3-rasvahappoja, eikosapentaeenihappoa (EPA) ja dokosaheksaeenihappoa (DHA) sekä D-vitamiinia. Silakassa esiintyvistä terveydelle haitallisista ympäristömyrkyistä tarkasteltiin dioksiineihin luettavia yhdisteitä, joihin kuuluvat polyklooratut dibentso-p-dioksiinit ja polyklooratut furaanit sekä dioksiininkaltaiset polyklooratut bifenyylit (PCB:t). Tulosten mukaan silakansyönti aiheuttaa Suomessa noin 11 (95 % luottamusväli LV 0 – 54) DALY kehityshäiriöistä (hammasvaurio) johtuvaa haittapainotettua elinvuotta (DALY), jotka kaikki kohdistuvat lapsiin äidin välityksellä raskausajan ja imetyksen kautta. Lisäksi silakansyönti aiheuttaa noin 12 (95 % LV 1.7 – 56) DALY dioksiinien aiheuttaman syöpäriskin kautta koko väestössä. Yli 50-vuotiailla naisilla ja varsinkin miehillä silakansyönnin terveyshyödyt ovat selkeästi suuremmat kuin terveyshaitat. Suurimmat terveyshyödyt saadaan sydäntautia ja sydänkuolleisuutta vähentävästä vaikutuksesta, noin -688 (95 % LV -2126 – -41) DALY/vuosi. Tulosten mukaan silakan syönti on vähentynyt väestössä niin paljon, että nykyiset suomalaiset kalan yleiset syöntisuositukset ovat riittävät suojaamaan väestöä dioksiinien ja dioksiinien kaltaisten yhdisteiden aiheuttamilta terveyshaitoilta. Hyöty-haitta-analyysissä tulisi kuitenkin tulevaisuudessa arvioida myös muiden rasvaisten kalojen keräämien ympäristömyrkkyjen kumulatiivisia terveysvaikutuksia ja yleisten syöntisuositusten riittävyyttä.Syftet med denna undersökning var att utreda om konsumtion av strömming från Östersjön ger mer hälsofördelar än hälsoskador i Finland och hurdant läget i olika ålderskategorier är. Tidigare nytta/riskvärderingar har visat att det i allmänhet är hälsosammare att äta fisk än att låta bli att göra det. Det beror särskilt på de hälsosamma omega-3-fettsyrorna i fisken. En stor del av fördelarna tillkommer ändå vuxna personer med förhöjd risk för hjärtsjukdomar och en stor del av skadorna tillkommer barn i form av risk för skador på tänderna och andra utvecklingsstörningar. På uppdrag från Evira och i samarbete med THL har under året 2014 gjorts en nytta/riskanalys, där man uttryckligen granskat olika ålderskategorier skilt för sig i ljuset av den nuvarande konsumtionen av strömming. Resultaten bygger på ett enkätmaterial som Taloustutkimus inhämtat år 2013. Utgående från detta material har sedan den egentliga granskningen av hälsoeffekterna gjorts. Resultaten angavs i form av funktionsjusterade levnadsår (Disability Adjusted Life Year DALY). För de nyttiga näringsämnenas del granskades i rapporten omega-3-fettsyrorna eikosapentaensyra (EPA) och dokosahexaensyra (DHA) och vitamin D. Av de hälsovådliga miljögifterna som förekommer i strömming granskades dioxiner, polyklorerade dibenzo-p-dioxinerna och plyklorerade dibenzofuranerna jämte dioxinliknande polyklorerade bifenylerna (PCB). Resultaten visar att konsumtion av strömming i Finland orsakar cirka 11 (95 % förtroende intervall , FI 0-54) funktionsjusterade levnadsår (DALY) som beror på utvecklingsstörningar (tandskada) och som alla via modern drabbar barn under graviditeten och amningen. Konsumtion av strömming medför också cirka 12 (95 %, FI 1,7-56) DALY via den cancerrisk som dioxinerna orsakar i hela befolkningen. Hos över 50 åriga kvinnor och framförallt män är fördelarna av att äta strömming klart större än hälsoskadorna. De största hälsofördelarna kommer av att risken för hjärtsjukdomar och dödligheten i hjärtsjukdomar minskar, cirka -688 (95 %, FI -2126 -41) DALY/år. Enligt resultaten konsumtion av strömming I Finland har sjunkit till en så låg nivå , att de nuvarande allmänna rekommenderade intagen av fisk konsumtion är tillräckliga för att skydda befolkningen mot hälsoskador av dioxiner eller dioxinlika föreningar. I risk-nytta-analys i framtiden bör ändå utvärderas totala hälsoeffekter av olika miljögifter i andra feta fiskarter ock kolla lämpligheten av rekommendationer av fisk konsumtion.The objective of this study was to determine whether the benefits of eating Baltic Sea herring exceed the risks in Finland, and what the situation is in different age groups. Previous risk-benefit analyses have shown that eating fish is in general healthier than not eating fish. This is particularly due to the healthy omega 3 fatty acids of fish. However, the benefits are largely enjoyed by adults with an elevated risk of heart disease, while children suffer the majority of the risks in the form of dental problems and other developmental disorders. In the riskbenefit analysis carried out to the order of Evira in collaboration with THL during 2014, different age groups were specifically considered separately in the light of current fish consumption. The results are based on the survey of the consumption of Baltic herring conducted by Taloustutkimus in 2013, which was used as the basis for the actual analysis of health effects. The results were expressed as Disability Adjusted Life Years (DALY). Omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) as well as vitamin D were analysed in the report as beneficial nutrients. As far as environmental toxins harmful to health are concerned, Baltic herring were analysed for compounds classified as dioxins, which include polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans, as well dioxin-like biphenyls (PCB). According to the results, in Finland eating herring causes ca. 11 (95% confidence interval, CI 0-54) Disability Adjusted Life Years (DALYs) resulting from developmental disorders (dental damage); these affect children via the mother during pregnancy and breastfeeding. In addition, eating herring causes a ca. 12 (95%, CI 1,7-56) DALY cancer risk due to dioxins in the entire population. The health benefits of eating herring clearly exceed risks to health for women and particularly men after the age of 50 years. The greatest health benefits result from the reduction in heart disease and heart-related fatality, ca. –688 (95%, CI -2126 -41) DALY/year. The results show that the consumption of Baltic herring has decreased in Finland to a low level and that the current common dietary advices on fish consumption are adequate to protect the population against the adverse health effects of dioxins and dioxin-like compounds. However, in risk benefit analysis in future it is important to estimate the total health effects of different environmental pollutants and of other fatty fish, and the sufficiency of dietary advices on fish consumption

High-resolution spatial patterns and drivers of terrestrial ecosystem carbon dioxide, methane, and nitrous oxide fluxes in the tundra

Arctic terrestrial greenhouse gas (GHG) fluxes of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) play an important role in the global GHG budget. However, these GHG fluxes are rarely studied simultaneously, and our understanding of the conditions controlling them across spatial gradients is limited. Here, we explore the magnitudes and drivers of GHG fluxes across fine-scale terrestrial gradients during the peak growing season (July) in sub-Arctic Finland. We measured chamber-derived GHG fluxes and soil temperature, soil moisture, soil organic carbon and nitrogen stocks, soil pH, soil carbon-to-nitrogen (C/N) ratio, soil dissolved organic carbon content, vascular plant biomass, and vegetation type from 101 plots scattered across a heterogeneous tundra landscape (5 km2). We used these field data together with high-resolution remote sensing data to develop machine learning models for predicting (i.e., upscaling) daytime GHG fluxes across the landscape at 2 m resolution. Our results show that this region was on average a daytime net GHG sink during the growing season. Although our results suggest that this sink was driven by CO2 uptake, it also revealed small but widespread CH4 uptake in upland vegetation types, almost surpassing the high wetland CH4 emissions at the landscape scale. Average N2O fluxes were negligible. CO2 fluxes were controlled primarily by annual average soil temperature and biomass (both increase net sink) and vegetation type, CH4 fluxes by soil moisture (increases net emissions) and vegetation type, and N2O fluxes by soil C/N (lower C/N increases net source). These results demonstrate the potential of high spatial resolution modeling of GHG fluxes in the Arctic. They also reveal the dominant role of CO2 fluxes across the tundra landscape but suggest that CH4 uptake in dry upland soils might play a significant role in the regional GHG budget.</p