EMERALD – Terrestrial ecosystem–climate interactions of our EMERALD planet

• Westergaard-Nielsen, Andreas; Maigaard, R S; Davie-Martin, Cleo Lisa; Seco, Roger; Holst, T & Pirk, Norbert [Vis alle 8 forfattere av denne artikkelen] (2025). Towards a remote-sensing-driven model of isoprene emissions from Alpine tundra. Environmental Research Letters. 20(10). doi: 10.1088/1748-9326/ae02a9. Fulltekst i vitenarkiv Vis sammendrag

  Abstract This study investigates isoprene emissions in a high-latitude Alpine tundra ecosystem, focusing on using near-field remote sensing of surface temperatures, the photochemical reflectance index (PRI) and normalized difference vegetation index (NDVI), and meteorological measurements to model these emissions. Isoprene is a key biogenic volatile organic compound (BVOC) emitted by select plants, which can impact atmospheric chemistry and climate. Increased temperatures, particularly in high latitudes, may enhance isoprene emissions due to extended growing seasons and heightened plant stress. The research was conducted in Finse, Norway, where isoprene and CO 2 fluxes were measured with eddy covariance alongside spectral and meteorological data, and surface temperature. A random forest (RF) model was developed to predict isoprene fluxes, considering the variable importance of different environmental factors. The results showed that surface temperature and CO 2 flux were consistently important predictors, across three differential temporal data aggregations (hourly, daily, weekly), while the PRI demonstrated low predictive power, possibly due to the heterogeneous vegetation and variable light conditions. The NDVI was more effective than anticipated, likely linked to phenological changes in vegetation. Model performance varied with temporal resolution, with weekly data achieving the highest predictive accuracy ( R 2 up to 0.76). The RF model accurately reflected seasonal emission patterns but underestimated short-term peaks, suggesting the potential to combine machine learning with process-based modelling. This research highlights the promise of proxy data from remote sensing for scaling BVOC emission models to regional levels, essential for understanding climate impacts in Arctic ecosystems.

• Finne, Eirik Aasmo; Bjerke, Jarle W.; Stordal, Frode & Tallaksen, Lena M. (2025). Lichens are more tolerant against winter warming stress than vascular and non-vascular plants: Insights from an alpine field experiment. Journal of Ecology. ISSN 0022-0477. 113(3), s. 518–530. doi: 10.1111/1365-2745.14482. Fulltekst i vitenarkiv Vis sammendrag

  Extreme weather events influence carbon cycling and lead to pervasive changes in ecosystem structure and function. Vegetation at high latitudes and in alpine bioclimatic zones can be particularly sensitive to winter warming events, which are short-lived climatic events where temperatures are unusually high and often include rainfall. With climate change the frequency and severity of winter warming events are increasing. We report here from a field experiment on a lichen-dominated ridge at a high mountain plateau in central Norway. This is a common vegetation type at high latitudes and altitudes, yet little is known about ecophysiological responses to winter warming events in lichens, and how it may differ from responses in bryophytes and vascular plants. We ran a week-long simulation of vegetation stress from winter warming events through thaw–freeze and ice encasement, during late winter in 2021 and 2022. The thaw–freeze treatment had minor effects on summer ecophysiology in lichens (Cladonia mitis, Cetraria islandica and Nephromopsis nivalis), while the species N. nivalis and to a lesser extent, C. mitis had reduced vitality after the ice encasement treatment. Contrastingly, the bryophyte Polytrichum juniperinum, and vascular plant Empetrum nigrum had reduced photosynthetic efficiency and seasonal growth in both thaw–freeze and ice encasement treatments. The ice encasement treatment was overall more lethal and led to reduced NDVI (Normalised Difference Vegetation Index). However, reduction in vitality of vascular and non-vascular plants was not enough to impact overall ecosystem carbon flux. Synthesis: The lichen's stronger tolerance against thaw–freeze and ice encasement than co-existing plants oppose the general effects of summer climate warming, where lichens may succumb under greater plant-growth and warmer soils. This study advocates for the importance of year-round ecology to understand vegetation change under climate change.

• Gallois, Elise C.; Myers-Smith, Isla H.; Iversen, Colleen M.; Salmon, Verity G.; Turner, Laura L. & An, Ruby [Vis alle 24 forfattere av denne artikkelen] (2025). Tundra Vegetation Community Type, Not Microclimate, Controls Asynchrony of Above- and Below-Ground Phenology. Global Change Biology. ISSN 1354-1013. 31(4). doi: 10.1111/gcb.70153. Fulltekst i vitenarkiv Vis sammendrag

  The below-ground growing season often extends beyond the above-ground growing season in tundra ecosystems and as the climate warms, shifts in growing seasons are expected. However, we do not yet know to what extent, when and where asynchrony in above- and below-ground phenology occurs and whether variation is driven by local vegetation communities or spatial variation in microclimate. Here, we combined above- and below-ground plant phenology metrics to compare the relative timings and magnitudes of leaf and fine-root growth and senescence across microclimates and plant communities at five sites across the Arctic and alpine tundra biome. We observed asynchronous growth between above- and below-ground plant tissue, with the below-ground season extending up to 74% (~56 days) beyond the onset of above-ground leaf senescence. Plant community type, rather than microclimate, was a key factor controlling the timing, productivity, and growth rates of fine roots, with graminoid roots exhibiting a distinct ‘pulse’ of growth later into the growing season than shrub roots. Our findings indicate the potential of vegetation change to influence below-ground carbon storage as the climate warms and roots remain active in unfrozen soils for longer. Taken together, our findings of increased root growth in soils that remain thawed later into the growing season, in combination with ongoing tundra vegetation change including increased shrub and graminoid abundance, indicate increased below-ground productivity and altered carbon cycling in the tundra biome.

• Keetz, Lasse Torben; Aalstad, Kristoffer; Fisher, Rosie; Terán, Christian Poppe; Naz, Bibi S. & Pirk, Norbert [Vis alle 8 forfattere av denne artikkelen] (2025). Inferring Parameters in a Complex Land Surface Model by Combining Data Assimilation and Machine Learning. Journal of Advances in Modeling Earth Systems. 17(6). doi: 10.1029/2024MS004542. Fulltekst i vitenarkiv Vis sammendrag

  Complex Land Surface Models (LSMs) rely on a plethora of parameters. These parameters and the associated process formulations are often poorly constrained, which hampers reliable predictions of ecosystem dynamics and climate feedbacks. Robust and uncertainty-aware parameter estimation with observations is complicated by, for example, the high dimensionality of the model parameter space and the computational cost of LSM simulations. Herein, we adapt a novel Bayesian data assimilation (DA) and machine learning framework termed “calibrate, emulate, sample” (CES) to infer parameters in a widely-used LSM coupled with a demographic vegetation model (CLM-FATES). First, an iterative ensemble Kalman smoother provides an initial estimate of the posterior distribution (“calibrate”). Subsequently, a machine-learning-based emulator is trained on the resulting model-observation mismatches to predict outcomes for unseen parameter combinations (“emulate”). Finally, this emulator replaces CLM-FATES simulations in an adaptive Markov Chain Monte Carlo approach enabling computationally feasible posterior sampling with enhanced uncertainty quantification (“sample”). We test our implementation with synthetic and real observations representing a boreal forest site in southern Finland. We estimate a total of six plant-functional-type-specific photosynthetic parameters by assimilating evapotranspiration (ET) and gross primary production (GPP) flux data. CES provided the best estimates of the synthetic truth parameters when compared to data-blind emulator sampling designs while all approaches reduced model-observation errors compared to a default parameter simulation (GPP: - 10% to - 30%, ET: -4% to -6%). Although errors were also consistently reduced with real data, comparing the emulator designs was less conclusive, which we mainly attribute to equifinality, structural uncertainty within CLM-FATES, and/or unknown errors in the data that are not accounted for.

• Zhu, Jiang; Tang, Hui; Fang, Keyan; Stordal, Frode; Bryn, Anders & Gao, Min [Vis alle 7 forfattere av denne artikkelen] (2025). Human Mediation of Wildfires and Its Representation in Terrestrial Ecosystem Models. Fire. 8(8). doi: 10.3390/fire8080297. Fulltekst i vitenarkiv Vis sammendrag

  Increasing wildfires are causing global concerns about ecosystem functioning and services. Although some wildfires are caused by natural ignitions, it is also important to understand how human ignitions and human-related factors can contribute to wildfires. While dynamic global vegetation models (DGVMs) have incorporated fire-related modules to simulate wildfires and their impacts, few models have fully considered various human-related factors causing human ignitions. Using global examples, this study aims to identify key factors associated with human impacts on wildfires and provides suggestions for enhancing model simulations. The main categories explored in this paper are human behavior and activities, socioeconomic background, policy, laws, regulations, and cultural and traditional activities, all of which can influence wildfires. Employing an integrated and interdisciplinary assessment approach, this study evaluates existing DGVMs and provides suggestions for their improvement.

• Bjerke, Jarle W.; Magnussen, Kristin; Bright, Ryan M.; Navrud, Ståle; Erlandsson, Rasmus & Finne, Eirik Aasmo [Vis alle 7 forfattere av denne artikkelen] (2024). Synergies and trade-offs between provisioning and climate-regulating ecosystem services in reindeer herding ecosystems. Science of the Total Environment. ISSN 0048-9697. 927. doi: 10.1016/j.scitotenv.2024.171914. Fulltekst i vitenarkiv Vis sammendrag

  Reindeer (Rangifer tarandus) pastoralism utilizes vast boreo-arctic taiga and tundra as grazing land. Highly fluctuating population sizes pose major challenges to the economy and livelihood of indigenous herder communities. In this study we investigated the effect of population fluctuations on core provisioning and regulating ecosystem services in two Sámi reindeer herding districts with contrasting fluctuation trends. We compared 50-year long time series on herd size, meat production, forage productivity, carbon footprint, and CO2-equivalence metrics for surface albedo change based on the radiative forcing concept. Our results show, for both districts, that the economic benefits from the provisioning services were higher than the costs from the regulating services. Still, there were major contrasts; the district with moderate and stable reindeer density gained nearly the double on provisioning services per unit area. The costs from increasing heat absorption due to reduction in surface albedo caused by replacement of high-reflective lichens with low-reflective woody plants, was 10.5 times higher per unit area in the district with large fluctuations. Overall, the net economic benefits per unit area were 237 % higher in the district with stable reindeer density. These results demonstrate that it is possible to minimize trade-offs between economic benefits from reindeer herding locally and global economic costs in terms of climate-regulating services by minimizing fluctuations in herds that are managed at sustainable densities.

• Aas, Elin Cecilie Ristorp; Althuizen, Inge; Tang, Hui; Geange, Sonya Rita; Lieungh, Eva & Vandvik, Vigdis [Vis alle 7 forfattere av denne artikkelen] (2024). Implications of climate and litter quality for simulations of litterbag decomposition at high latitudes. Biogeosciences. ISSN 1726-4170. 21(16), s. 3789–3817. doi: 10.5194/bg-21-3789-2024. Fulltekst i vitenarkiv Vis sammendrag

  Litter decomposition is a vital part of the carbon cycle and is thoroughly studied both in the field and with models. Although temporally and spatially limited, litterbag decomposition experiments are often used to calibrate and evaluate soil models, coupled to land models, that are intended for use on large scales. We used the microbially explicit soil decomposition model MIMICS+ to replicate two high-latitude litterbag decomposition experiments of different spatial and temporal scales. We investigated how well the model represented observed mass loss in terms of the controlling factors of climate and litter quality and their relative importance with time. In addition to default model forcing, we used measured and site-specific model-derived microclimatic variables (soil moisture and temperature), hypothesizing that this would improve model results. We found that MIMICS+ represented mass loss after 1, 3, and 6 years well across a climatic gradient of Canadian sites but had more variable results for 1-year mass loss across a climate grid in southern Norway. In terms of litter quality, the litter metabolic fraction had more influence on modeled mass loss than the carbon-to-nitrogen ratio of the litter. Using alternative microclimate sources led to up to 23 % more mass remaining and down to 22 % less mass remaining compared to the simulations using default model inputs. None of the input alternatives significantly improved results compared to using the default model setup. We discuss possible causes for our findings and suggest measures to better utilize short-term field experiments to inform microbially explicit decomposition models.

• Cassiani, Massimo; Ardeshiri, Hamidreza; Pisso, Ignacio; Salizzoni, Pietro; Marro, Massimo & Stohl, Andreas [Vis alle 8 forfattere av denne artikkelen] (2024). The dynamics of concentration fluctuations within passive scalar plumes in a turbulent neutral boundary layer. Journal of Fluid Mechanics. ISSN 0022-1120. 1001. doi: 10.1017/jfm.2024.861. Fulltekst i vitenarkiv Vis sammendrag

  We investigate the concentration fluctuations of passive scalar plumes emitted from small, localised (point-like) steady sources in a neutrally stratified turbulent boundary layer over a rough wall. The study utilises high-resolution large-eddy simulations for sources of varying sizes and heights. The numerical results, which show good agreement with wind-tunnel studies, are used to estimate statistical indicators of the concentration field, including spectra and moments up to the fourth order. These allow us to elucidate the mechanisms responsible for the production, transport and dissipation of concentration fluctuations, with a focus on the very near field, where the skewness is found to have negative values – an aspect not previously highlighted. The gamma probability density function is confirmed to be a robust model for the one-point concentration at sufficiently large distances from the source. However, for ground-level releases in a well-defined area around the plume centreline, the Gaussian distribution is found to be a better statistical model. As recently demonstrated by laboratory results, for elevated releases, the peak and shape of the pre-multiplied scalar spectra are confirmed to be independent of the crosswind location for a given downwind distance. Using a stochastic model and theoretical arguments, we demonstrate that this is due to the concentration spectra being directly shaped by the transverse and vertical velocity components governing the meandering of the plume. Finally, we investigate the intermittency factor, i.e. the probability of non-zero concentration, and analyse its variability depending on the thresholds adopted for its definition.

• Aas, Elin Cecilie Ristorp; Wit, Heleen de & Berntsen, Terje Koren (2024). Modeling boreal forest soil dynamics with the microbially explicit soil model MIMICS+ (v1.0). Geoscientific Model Development. ISSN 1991-959X. 17(7), s. 2929–2959. doi: 10.5194/gmd-17-2929-2024. Fulltekst i vitenarkiv Vis sammendrag

  Understanding carbon exchange processes between land reservoirs and the atmosphere is essential for predicting carbon–climate feedbacks. Still, considerable uncertainty remains in the representation of the terrestrial carbon cycle in Earth system models. An emerging strategy to constrain these uncertainties is to include the role of different microbial groups explicitly. Following this approach, we extend the framework of the MIcrobial-MIneral Carbon Stabilization (MIMICS) model with additional mycorrhizal groups and a nitrogen cycle that includes a novel representation of inorganic nitrogen sorption to particles via a Langmuir isotherm. MIMICS+ v1.0 is designed to capture and quantify relationships between soil microorganisms and their environment, with a particular emphasis on boreal ecosystems. We evaluated MIMICS+ against podzolic soil profiles in Norwegian forests as well as the conventional Community Land Model (CLM). MIMICS+ matched observed carbon stocks better than CLM and gave a broader range of C:N

• Pirk, Norbert; Aalstad, Kristoffer; Mannerfelt, Erik Schytt; Clayer, Francois; Wit, Heleen de & Christiansen, Casper Tai [Vis alle 9 forfattere av denne artikkelen] (2024). Disaggregating the Carbon Exchange of Degrading Permafrost Peatlands Using Bayesian Deep Learning. Geophysical Research Letters. ISSN 0094-8276. 51(10). doi: 10.1029/2024GL109283. Fulltekst i vitenarkiv Vis sammendrag

  Extensive regions in the permafrost zone are projected to become climatically unsuitable to sustain permafrost peatlands over the next century, suggesting transformations in these landscapes that can leave large amounts of permafrost carbon vulnerable to post-thaw decomposition. We present 3 years of eddy covariance measurements of CH4 and CO2 fluxes from the degrading permafrost peatland Iškoras in Northern Norway, which we disaggregate into separate fluxes of palsa, pond, and fen areas using information provided by the dynamic flux footprint in a novel ensemble-based Bayesian deep neural network framework. The 3-year mean CO2-equivalent flux is estimated to be 106 gCO2 m−2 yr−1 for palsas, 1,780 gCO2 m−2 yr−1 for ponds, and −31 gCO2 m−2 yr−1 for fens, indicating that possible palsa degradation to thermokarst ponds would strengthen the local greenhouse gas forcing by a factor of about 17, while transformation into fens would slightly reduce the current local greenhouse gas forcing.

• Keetz, Lasse Torben; Lieungh, Eva; Karimi-Asli, Kaveh; Geange, Sonya Rita; Gelati, Emiliano & Tang, Hui [Vis alle 24 forfattere av denne artikkelen] (2023). Climate–ecosystem modelling made easy: The Land Sites Platform. Global Change Biology. ISSN 1354-1013. 29(15), s. 4440–4452. doi: 10.1111/gcb.16808. Fulltekst i vitenarkiv Vis sammendrag

  Dynamic Global Vegetation Models (DGVMs) provide a state-of-the-art process-based approach to study the complex interplay between vegetation and its physical environment. For example, they help to predict how terrestrial plants interact with climate, soils, disturbance and competition for resources. We argue that there is untapped potential for the use of DGVMs in ecological and ecophysiological research. One fundamental barrier to realize this potential is that many researchers with relevant expertize (ecology, plant physiology, soil science, etc.) lack access to the technical resources or awareness of the research potential of DGVMs. Here we present the Land Sites Platform (LSP): new software that facilitates single-site simulations with the Functionally Assembled Terrestrial Ecosystem Simulator, an advanced DGVM coupled with the Community Land Model. The LSP includes a Graphical User Interface and an Application Programming Interface, which improve the user experience and lower the technical thresholds for installing these model architectures and setting up model experiments. The software is distributed via version-controlled containers; researchers and students can run simulations directly on their personal computers or servers, with relatively low hardware requirements, and on different operating systems. Version 1.0 of the LSP supports site-level simulations. We provide input data for 20 established geo-ecological observation sites in Norway and workflows to add generic sites from public global datasets. The LSP makes standard model experiments with default data easily achievable (e.g., for educational or introductory purposes) while retaining flexibility for more advanced scientific uses. We further provide tools to visualize the model input and output, including simple examples to relate predictions to local observations. The LSP improves access to land surface and DGVM modelling as a building block of community cyberinfrastructure that may inspire new avenues for mechanistic ecosystem research across disciplines.

• Jaroszynska, Francesca Orinda Holl; Althuizen, Inge; Rechsteiner, Aud Helen Halbritter; Klanderud, Kari; Lee, Hanna & Telford, Richard James [Vis alle 7 forfattere av denne artikkelen] (2023). Bryophytes dominate plant regulation of soil microclimate in alpine grasslands. Oikos. ISSN 0030-1299. 2023(12). doi: 10.1111/oik.10091. Fulltekst i vitenarkiv Vis sammendrag

  Soil temperature and moisture are important regulators of a broad range of biotic and abiotic processes in terrestrial ecosystems. Vegetation can, in turn, play a role in regulating soil microclimate, which creates potential for powerful and interactive feedbacks from soil and vegetation on the atmosphere. Although the regulatory effect of vegetation on soil microclimatic conditions has been quite extensively and empirically assessed, most studies have determined the net effect of intact woody vegetation versus bare ground. However, for other plant functional groups we lack a clear understanding of their role and any climate-context dependency in controlling microclimatic conditions. We investigated the role of three major plant functional groups – graminoids, forbs and bryophytes – in regulating soil microclimate in semi-natural alpine grasslands. Using a fully factorial above-ground biomass removal experiment, we assessed the role of these plant functional groups in regulating soil temperature amplitude, soil moisture, and number of freezing days. The experiment was replicated across orthogonal temperature and precipitation gradients in Norway to assess whether the effects of functional group abundance varied with climate. The effect of plant biomass on soil microclimate varied among functional groups across the climatic gradients. Bryophytes reduced growing season soil temperature, whereas graminoids and forbs did not (0.5ºC compared to 0ºC), and with a stronger effect in colder climates at higher elevations and on days with high solar radiation. Bryophyte biomass further reduced the number of soil freezing days at boreal and sub-alpine sites. Finally, graminoid biomass partly explained variation in soil moisture: soils dried more under graminoids at drier sites. Our findings highlight that functional group identity plays a key role in regulating soil microclimate in alpine grasslands across seasons. The strong effect of bryophytes on soil temperature points to their importance in the plant community for a variety of ecosystem functions, some of which may be indirectly vulnerable to future warming via biomass reductions of bryophytes.

• Jiao, Yi; Davie-Martin, Cleo L.; Kramshøj, Magnus; Christiansen, Casper Tai; Lee, Hanna & Althuizen, Inge [Vis alle 7 forfattere av denne artikkelen] (2023). Volatile organic compound release across a permafrost-affected peatland. Geoderma. ISSN 0016-7061. 430. doi: 10.1016/j.geoderma.2023.116355. Fulltekst i vitenarkiv Vis sammendrag

  As the permafrost region experiences unprecedented climate warming, accelerated decomposition rates are potentially switching these cold landscapes to a hotspot of carbon emissions. In addition to the more widely studied greenhouse gases, carbon dioxide and methane, permafrost-affected soils may also be a source of volatile organic compounds (VOCs), but these reactive trace gases have so far received little attention. Nevertheless, VOCs can i) prolong the lifetime of atmospheric methane, ii) contribute to hazardous ozone production, and iii) lead to the formation of secondary organic aerosols. Consequently, changing VOC emissions may exert significant impacts on climate forcing factors that can both exacerbate or mitigate future climate change. Here, we conducted in situ measurements of soil and pond VOC emissions across an actively degrading permafrost-affected peatland in subarctic Norway. We used a permafrost thaw gradient as a space-for-time substitute that covered bare soil and vegetated peat plateaus, underlain by intact permafrost, and increasingly degraded permafrost landscapes: thaw slumps, thaw ponds, and vegetated thaw ponds. Results showed that every peatland landscape type was an important source of atmospheric VOCs, emitting a large variety of compounds, such as methanol, acetone, monoterpenes, sesquiterpenes, isoprene, hydrocarbons, and oxygenated VOCs. VOC composition varied considerably across the measurement period and across the permafrost thaw gradient. We observed enhanced terpenoid emissions following thaw slump degradation, highlighting the potential atmospheric impacts of permafrost thaw, due to the high chemical reactivities of terpenoid compounds. Higher VOC emission rates were observed in summer (June, July and August) compared to early autumn (September). Overall, our study demonstrates that VOCs are being emitted in significant quantities and with largely similar compositions upon permafrost thawing, inundation, and subsequent vegetation development, despite major differences in microclimate, hydrological regime, vegetation, and permafrost occurrence.

• Finne, Eirik Aasmo; Bjerke, Jarle W.; Erlandsson, Rasmus; Tømmervik, Hans; Stordal, Frode & Tallaksen, Lena M. (2023). Variation in albedo and other vegetation characteristics in non-forested northern ecosystems: the role of lichens and mosses. Environmental Research Letters. 18(7). doi: 10.1088/1748-9326/ace06d. Fulltekst i vitenarkiv Vis sammendrag

  Vegetation has a profound impact on climate through complex interactions and feedback loops, where especially regulation of albedo, the ratio of reflected to incoming solar radiation, is important at high latitudes. How vegetation albedo varies along environmental gradients in tundra ecosystems is still not well understood, particularly for ecosystems dominated by nonvascular vegetation. We studied broadband shortwave albedo of open boreal, arctic, and alpine ecosystems over a 2000 km long latitudinal gradient (60◦ N–79◦ N) and contrasted this against species composition, vegetation greenness (normalised difference vegetation index—NDVI), momentary ecosystem CO2 fluxes and reindeer (Rangifer tarandus) grazing pressure. High cover of pale terricolous fruticose lichens was the single most important predictor for vegetation albedo, which had a maximum value of 0.389 under clear sky conditions and solar zenith angle 60◦. To our knowledge, this is the highest broadband albedo recorded for a vegetated surface. NDVI was negatively correlated to lichen biomass (rs = −0.56), and albedo (rs = −0.19). Gross primary production and ecosystem respiration varied considerably less between plots and vegetation types than albedo. While it is well-known that Rangifer affects climate-relevant aboveground biomass, we here show that its regulation of surface albedo in northern ecosystems may also be of high importance for land-atmosphere interactions. The data presented here thus advocate for an increased understanding of the important and complex role of herbivores and lichen cover in climate-vegetation interactions.

• Naas, Adam Eindride; Halvorsen, Rune; Horvath, Peter; Wollan, Anders Kvalvåg; Bratli, Harald & Brynildsrud, Katrine Marie [Vis alle 16 forfattere av denne artikkelen] (2023). What explains inconsistencies in field-based ecosystem mapping? Applied Vegetation Science. ISSN 1402-2001. 26(1). doi: 10.1111/avsc.12715. Fulltekst i vitenarkiv Vis sammendrag

  Questions Field-based ecosystem mapping is prone to observer bias, typically resulting in a mismatch between maps made by different mappers, that is, inconsistency. Experimental studies testing the influence of site, mapping scale, and differences in experience level on inconsistency in field-based ecosystem mapping are lacking. Here, we study how inconsistencies in field-based ecosystem maps depend on these factors. Location Iškoras and Guollemuorsuolu, northeastern Norway, and Landsvik and Lygra, western Norway. Methods In a balanced experiment, four sites were field-mapped wall-to-wall to scales 1:5000 and 1:20,000 by 12 mappers, representing three experience levels. Thematic inconsistency was calculated by overlay analysis of map pairs from the same site, mapped to the same scale. We tested for significant differences between sites, scales, and experience-level groups. Principal components analysis was used in an analysis of additional map inconsistencies and their relationships with site, scale and differences in experience level and time consumption were analysed with redundancy analysis. Results On average, thematic inconsistency was 51%. The most important predictor for thematic inconsistency, and for all map inconsistencies, was site. Scale and its interaction with site predicted map inconsistencies, but only the latter were important for thematic inconsistency. The only experience-level group that differed significantly from the mean thematic inconsistency was that of the most experienced mappers, with nine percentage points. Experience had no significant effect on map inconsistency as a whole. Conclusion Thematic inconsistency was high for all but the dominant thematic units, with potentially adverse consequences for mapping ecosystems that are fragmented or have low coverage. Interactions between site and mapping system properties are considered the main reasons why no relationships between scale and thematic inconsistency were observed. More controlled experiments are needed to quantify the effect of other factors on inconsistency in field-based mapping.

• Wang, You-Ren; Samset, Bjørn Hallvard; Stordal, Frode; Bryn, Anders & Hessen, Dag Olav (2023). Past and future trends of diurnal temperature range and their correlation with vegetation assessed by MODIS and CMIP6. Science of the Total Environment. ISSN 0048-9697. 904. doi: 10.1016/j.scitotenv.2023.166727. Fulltekst i vitenarkiv
• Lambert, Marius; Tang, Hui; Aas, Kjetil Schanke; Stordal, Frode; Fisher, Rosie & Bjerke, Jarle Werner [Vis alle 8 forfattere av denne artikkelen] (2023). Integration of a Frost Mortality Scheme Into the Demographic Vegetation Model FATES. Journal of Advances in Modeling Earth Systems. 15(7). doi: 10.1029/2022MS003333. Fulltekst i vitenarkiv Vis sammendrag

  Frost is damaging to plants when air temperature drops below their tolerance threshold. The set of mechanisms used by cold-tolerant plants to withstand freezing is called “hardening” and typically take place in autumn to protect against winter damage. The recent incorporation of a hardening scheme in the demographic vegetation model FATES opens up the possibility to investigate frost mortality to vegetation. Previously, the hardening scheme was used to improve hydraulic processes in cold-tolerant plants. In this study, we expand upon the existing hardening scheme by implementing hardiness-dependent frost mortality into CLM5.0-FATES to study the impacts of frost on vegetation in temperate and boreal sites from 1950 to 2015. Our results show that the original freezing mortality approach of FATES, where each plant type had a fixed freezing tolerance threshold—an approach common to many other dynamic vegetation models, was restricted to predicting plant type distribution. The main results emerging from the new scheme are a high autumn and spring frost mortality, especially at colder sites, and increasing mid-winter frost mortality due to global warming, especially at warmer sites. We demonstrate that the new frost scheme is a major step forward in dynamically representing vegetation in ESMs by for the first time including a level of frost tolerance that is responding to the environment and includes some level of cost (implicitly) and benefit. By linking hardening and frost mortality in a land surface model, we open new ways to explore the impact of frost events in the context of global warming.

• Pirk, Norbert; Aalstad, Kristoffer; Yilmaz, Yeliz A.; Vatne, Astrid; Popp, Andrea & Horvath, Peter [Vis alle 12 forfattere av denne artikkelen] (2023). Snow-vegetation-atmosphere interactions in alpine tundra. Biogeosciences. ISSN 1726-4170. 20(11), s. 2031–2047. doi: 10.5194/bg-20-2031-2023. Fulltekst i vitenarkiv Vis sammendrag

  The interannual variability of snow cover in alpine areas is increasing, which may affect the tightly coupled cycles of carbon and water through snow–vegetation–atmosphere interactions across a range of spatio-temporal scales. To explore the role of snow cover for the land–atmosphere exchange of CO2 and water vapor in alpine tundra ecosystems, we combined 3 years (2019–2021) of continuous eddy covariance flux measurements of the net ecosystem exchange of CO2 (NEE) and evapotranspiration (ET) from the Finse site in alpine Norway (1210 m a.s.l.) with a ground-based ecosystem-type classification and satellite imagery from Sentinel-2, Landsat 8, and MODIS. While the snow conditions in 2019 and 2021 can be described as site typical, 2020 features an extreme snow accumulation associated with a strong negative phase of the Scandinavian pattern of the synoptic atmospheric circulation during spring. This extreme snow accumulation caused a 1-month delay in melt-out date, which falls in the 92nd percentile in the distribution of yearly melt-out dates in the period 2001–2021. The melt-out dates follow a consistent fine-scale spatial relationship with ecosystem types across years. Mountain and lichen heathlands melt out more heterogeneously than fens and flood plains, while late snowbeds melt out up to 1 month later than the other ecosystem types. While the summertime average normalized difference vegetation index (NDVI) was reduced considerably during the extreme-snow year 2020, it reached the same maximum as in the other years for all but one of the ecosystem types (late snowbeds), indicating that the delayed onset of vegetation growth is compensated to the same maximum productivity. Eddy covariance estimates of NEE and ET are gap-filled separately for two wind sectors using a random forest regression model to account for complex and nonlinear ecohydrological interactions. While the two wind sectors differ markedly in vegetation composition and flux magnitudes, their flux response is controlled by the same drivers as estimated by the predictor importance of the random forest model, as well as by the high correlation of flux magnitudes (correlation coefficient r=0.92 for NEE and r=0.89 for ET) between both areas. The 1-month delay of the start of the snow-free season in 2020 reduced the total annual ET by 50 % compared to 2019 and 2021 and reduced the growing-season carbon assimilation to turn the ecosystem from a moderate annual carbon sink (−31 to −6 gC m−2 yr−1) to a source (34 to 20 gC m−2 yr−1). These results underpin the strong dependence of ecosystem structure and functioning on snow dynamics, whose anomalies can result in important ecological extreme events for alpine ecosystems.

• Erlandsson, Rasmus; Arneberg, Marit Klemetsen; Tømmervik, Hans; Finne, Eirik Aasmo; Nilsen, Lennart & Bjerke, Jarle W. (2023). Feasibility of active handheld NDVI sensors for monitoring of lichen ground cover. Fungal ecology. ISSN 1754-5048. 63. doi: 10.1016/j.funeco.2023.101233. Fulltekst i vitenarkiv Vis sammendrag

  Vegetation indices are corner stones in vegetation monitoring. However, previous field studies on lichens and NDVI have been based on passive sensors. Active handheld sensors, with their own light sources, enables high-precision monitoring under variable ambient conditions. We investigated the use of handheld sensor NDVI for monitoring pale lichen cover across three study sites from boreal heathlands to High Arctic tundra (62–79 °N), and compared it with Sentinel-2 satellite NDVI. NDVI decreased with increasing cover of pale lichens but the correlation between active and satellite NDVI varied between areas. NDVI values declined with lichen cover and ranged from 0.4–0.18 when lichen cover was above 40%. Active ground measurements of NDVI explained 81% of the variation in the satellite NDVI values in Svalbard (High Arctic), while the relationships were lower (∼30% explained variation) in boreal regions (Troms-Finnmark and Røros). We show that active sensors are feasible for extracting information from lichen-dominated vegetation. Lichen, Pale lichens, Cladonia, NDVI, Active sensor, Remote sensing, Monitoring

• Lambert, Marius; Tang, Hui; Aas, Kjetil Schanke; Stordal, Frode; Fisher, Rosie & Fang, Yilin [Vis alle 8 forfattere av denne artikkelen] (2022). Inclusion of a cold hardening scheme to represent frost tolerance is essential to model realistic plant hydraulics in the Arctic-boreal zone in CLM5.0-FATES-Hydro. Geoscientific Model Development. ISSN 1991-959X. 15(23), s. 8809–8829. doi: 10.5194/gmd-15-8809-2022. Fulltekst i vitenarkiv Vis sammendrag

  As temperatures decrease in autumn, vegetation of temperate and boreal ecosystems increases its tolerance to freezing. This process, known as hardening, results in a set of physiological changes at the molecular level that initiate modifications of cell membrane composition and the synthesis of anti-freeze proteins. Together with the freezing of extracellular water, anti-freeze proteins reduce plant water potentials and xylem conductivity. To represent the responses of vegetation to climate change, land surface schemes increasingly employ “hydrodynamic” models that represent the explicit fluxes of water from soil and through plants. The functioning of such schemes under frozen soil conditions, however, is poorly understood. Nonetheless, hydraulic processes are of major importance in the dynamics of these systems, which can suffer from, e.g., winter “frost drought” events. In this study, we implement a scheme that represents hardening into CLM5.0-FATES-Hydro. FATES-Hydro is a plant hydrodynamics module in FATES, a cohort model of vegetation physiology, growth, and dynamics hosted in CLM5.0. We find that, in frozen systems, it is necessary to introduce reductions in plant water loss associated with hardening to prevent winter desiccation. This work makes it possible to use CLM5.0-FATES-Hydro to model realistic impacts from frost droughts on vegetation growth and photosynthesis, leading to more reliable projections of how northern ecosystems respond to climate change.

• Jonsdottir, Ingibjørg; Rechsteiner, Aud Helen Halbritter; Christiansen, Casper Tai; Althuizen, Inge; Haugum, Siri Vatsø & Henn, Jonathan J. [Vis alle 15 forfattere av denne artikkelen] (2022). Intraspecific trait variability is a key feature underlying high Arctic plant community resistance to climate warming. Ecological Monographs. ISSN 0012-9615. 93(1). doi: 10.1002/ecm.1555. Fulltekst i vitenarkiv Vis sammendrag

  In the high Arctic, plant community species composition generally responds slowly to climate warming, whereas less is known about the community functional trait responses and consequences for ecosystem functioning. The slow species turnover and large distribution ranges of many Arctic plant species suggest a significant role of intraspecific trait variability in functional responses to climate change. Here we compare taxonomic and functional community compositional responses to a long-term (17-year) warming experiment in Svalbard, Norway, replicated across three major high Arctic habitats shaped by topography and contrasting snow regimes. We observed taxonomic compositional changes in all plant communities over time. Still, responses to experimental warming were minor and most pronounced in the drier habitats with relatively early snowmelt timing and long growing seasons (Cassiope and Dryas heaths). The habitats were clearly separated in functional trait space, defined by 12 size- and leaf economics-related traits, primarily due to interspecific trait variation. Functional traits also responded to experimental warming, most prominently in the Dryas heath and mostly due to intraspecific trait variation. Leaf area and mass increased and leaf δ15N decreased in response to the warming treatment. Intraspecific trait variability ranged between 30% and 71% of the total trait variation, reflecting the functional resilience of those communities, dominated by long-lived plants, due to either phenotypic plasticity or genotypic variation, which most likely underlies the observed resistance of high Arctic vegetation to climate warming. We further explored the consequences of trait variability for ecosystem functioning by measuring peak season CO2 fluxes. Together, environmental, taxonomic, and functional trait variables explained a large proportion of the variation in net ecosystem exchange (NEE), which increased when intraspecific trait variation was accounted for. In contrast, even though ecosystem respiration and gross ecosystem production both increased in response to warming across habitats, they were mainly driven by the direct kinetic impacts of temperature on plant physiology and biochemical processes. Our study shows that long-term experimental warming has a modest but significant effect on plant community functional trait composition and suggests that intraspecific trait variability is a key feature underlying high Arctic ecosystem resistance to climate warming.

• Haider, Sylvia; Lembrechts, Jonas J.; McDougall, Keith; Pauchard, Aníbal; Alexander, Jake M. & Barros, Agustina [Vis alle 58 forfattere av denne artikkelen] (2022). Think globally, measure locally: The MIREN standardized protocol for monitoring plant species distributions along elevation gradients. Ecology and Evolution. 12(2). doi: 10.1002/ece3.8590. Fulltekst i vitenarkiv Vis sammendrag

  Climate change and other global change drivers threaten plant diversity in mountains worldwide. A widely documented response to such environmental modifications is for plant species to change their elevational ranges. Range shifts are often idiosyncratic and difficult to generalize, partly due to variation in sampling methods. There is thus a need for a standardized monitoring strategy that can be applied across mountain regions to assess distribution changes and community turnover of native and non-native plant species over space and time. Here, we present a conceptually intuitive and standardized protocol developed by the Mountain Invasion Research Network (MIREN) to systematically quantify global patterns of native and non-native species distributions along elevation gradients and shifts arising from interactive effects of climate change and human disturbance. Usually repeated every five years, surveys consist of 20 sample sites located at equal elevation increments along three replicate roads per sampling region. At each site, three plots extend from the side of a mountain road into surrounding natural vegetation. The protocol has been successfully used in 18 regions worldwide from 2007 to present. Analyses of one point in time already generated some salient results, and revealed region-specific elevational patterns of native plant species richness, but a globally consistent elevational decline in non-native species richness. Non-native plants were also more abundant directly adjacent to road edges, suggesting that disturbed roadsides serve as a vector for invasions into mountains. From the upcoming analyses of time series, even more exciting results can be expected, especially about range shifts. Implementing the protocol in more mountain regions globally would help to generate a more complete picture of how global change alters species distributions. This would inform conservation policy in mountain ecosystems, where some conservation policies remain poorly implemented.

• Bryn, Anders & Potthoff, Kerstin (2022). Assessing the impact of climate change versus land use on tree- and forest line dynamics in Norway. I Schickhoff, Udo; Singh, R.B. & Mal, Suraj (Red.), Mountain Landscapes in Transition. Effects of Land Use and Climate Change. Springer Nature. ISSN 9783030702373. s. 613–626. doi: 10.1007/978-3-030-70238-0_29. Fulltekst i vitenarkiv
• Hessen, Dag Olav & Vandvik, Vigdis (2022). Buffering climate change with nature. Weather, Climate, and Society. ISSN 1948-8327. 14(2), s. 439–450. doi: 10.1175/WCAS-D-21-0059.1. Fulltekst i vitenarkiv Vis sammendrag

  It is increasingly evident that climate sustainability depends not only on societal actions and responses, but also on ecosystem functioning and responses. The capacity of global ecosystems to provide services such as sequestering carbon and regulating hydrology is being strongly reduced both by climate change itself and by unprecedented rates of ecosystem degradation. These services rely on functional aspects of ecosystems that are causally linked—the same ecosystem components that efficiently sequester and store carbon also regulate hydrology by sequestering and storing water. This means that climate change adaptation and mitigation must involve not only preparing for a future with temperature and precipitation anomalies, but also actively minimizing climate hazards and risks by conserving and managing ecosystems and their fundamental supporting and regulating ecosystem services. We summarize general climate–nature feedback processes relating to carbon and water cycling on a broad global scale before focusing on Norway to exemplify the crucial role of ecosystem regulatory services for both carbon sequestration and hydrological processes and the common neglect of this ecosystem–climate link in policy and landscape management. We argue that a key instrument for both climate change mitigation and adaptation policy is to take advantage of the climate buffering and regulative abilities of a well-functioning natural ecosystem. This will enable shared benefits to nature, climate, and human well-being. To meet the global climate and nature crises, we must capitalize on the importance of nature for buffering climate change effects, combat short-term perspectives and the discounting of future costs, and maintain or even strengthen whole-ecosystem functioning at the landscape level.

• Wang, You-Ren; Buchmann, Nina; Hessen, Dag Olav; Stordal, Frode; Erisman, Jan Willem & Vollsnes, Ane Victoria [Vis alle 8 forfattere av denne artikkelen] (2022). Disentangling effects of natural and anthropogenic drivers on forest net ecosystem production. Science of the Total Environment. ISSN 0048-9697. 839. doi: 10.1016/j.scitotenv.2022.156326. Fulltekst i vitenarkiv Vis sammendrag

  Net Ecosystem Production (NEP) of forests is the net carbon dioxide (CO2) fluxes between land and the atmosphere due to forests' biogeochemical processes. NEP varies with natural drivers such as precipitation, air temperature, solar radiation, plant functional type (PFT), and soil texture, which affect the gross primary production and ecosystem respiration, and thus the net C sequestration. It is also known that deposition of sulphur and nitrogen influences NEP in forest ecosystems. These drivers' respective, unique effects on NEP, however, are often difficult to be individually identified by conventional bivariate analysis. Here we show that by analyzing 22 forest sites with 231 site-year data acquired from FLUXNET database across Europe for the years 2000–2014, the individual, unique effects of these drivers on annual forest CO2 fluxes can be disentangled using Generalized Additive Models (GAM) for nonlinear regression analysis. We show that S and N deposition have substantial impacts on NEP, where S deposition above 5 kg S ha−1 yr−1 can significantly reduce NEP, and N deposition around 22 kg N ha−1 yr−1 has the highest positive effect on NEP. Our results suggest that air quality management of S and N is crucial for maintaining healthy biogeochemical functions of forests to mitigate climate change. Furthermore, the empirical models we developed for estimating NEP of forests can serve as a forest management tool in the context of climate change mitigation. Potential applications include the assessment of forest carbon fluxes in the REDD+ framework of the UNFCCC.

Se alle arbeider i NVA

• Bryn, Anders; Wal, René Van der; Norton, Lisa & Hofmeester, Tim R. (2023). Citizen science: data collection by volunteers. Routledge. ISBN 9781003179245. 14 s. Fulltekst i vitenarkiv

Se alle arbeider i NVA

• Muzic, Iris; Hodnebrog, Øivind; Yilmaz, Yeliz A.; Berntsen, Terje Koren; Sillmann, Jana & Lawrence, David M. [Vis alle 8 forfattere av denne artikkelen] (2025). Evaluating Land-Atmosphere Interactions in the coupled WRF-CTSM model over Nordic Fennoscandia. Fulltekst i vitenarkiv Vis sammendrag

  High latitude regions are experiencing rapid changes under evolving climate conditions. Advanced research tools are essential for understanding these dynamics and their associated feedback mechanisms. Here we present 1) a comprehensive evaluation of the state-of-the-art coupled regional climate model WRF–CTSM in simulating hydroclimatic variables and 2) soil moisture–temperature coupling analysis during the extreme 2018 heatwave. The WRF–CTSM model couples the Weather Research and Forecasting (WRF) model with the Community Terrestrial Systems Model (CTSM) which enables a more detailed representation of land surface processes and their interactions with the atmosphere. We conducted a high-resolution (10.5 km) 13-year simulation (2010–2022) over Nordic Fennoscandia (Norway, Sweden, and Finland) to assess the model’s performance in capturing key hydroclimatic variables such as mean, minimum, and maximum 2 m temperatures, precipitation, snow variables (snow depth, snow water equivalent, fractional snow‐covered duration), and surface energy balance components. A multi-source comparison using gridded, satellite-based, and in situ observations indicates that the WRF–CTSM model effectively captures high latitude climate conditions at different timescales. In addition, we used WRF–CTSM to investigate soil moisture–temperature coupling during the 2018 heatwave with a focus on southern and central Sweden that is considered as a coupling hotspot. A multi-correlation overlay analysis was performed using four different WRF–CTSM configurations. We employed a gridded observational dataset as a reference after validating against in situ measurements to assess the magnitude and variability of the key coupling variables. Our results show that soil moisture–temperature coupling persisted for an average of 40 days. The atmospheric leg contributes on average 88% of the coupling duration with considerable variability across datasets. Our findings highlight the capability of the WRF–CTSM model to simulate complex land–atmosphere interactions in high latitude environments

• Vandvik, Vigdis (2024). Forvaltning av natur for fremtiden. Fulltekst i vitenarkiv
• Vandvik, Vigdis & Leine, Jan Erlend (2024). Den fantastiske fotosyntesen. [Radio]. NRK - Ekko i P2. Fulltekst i vitenarkiv
• Erlandsson, Rasmus; Finne, Eirik Aasmo; Tømmervik, Hans; Stordal, Frode & Tallaksen, Lena M. (2024). Pan-arctic lichen estimation indicates a shift from herbivory to climate change driven declines in lichen biomass. Fulltekst i vitenarkiv
• Bjerke, Jarle Werner & Finne, Eirik Aasmo (2023). Arctic Climate Change and its impacts. Fulltekst i vitenarkiv
• Finne, Eirik Aasmo (2023). On the climatic effects of lichens. Fulltekst i vitenarkiv
• Vandvik, Vigdis (2023). Dyrebare myr. [Internet]. Klimafestvalen Varmere-Våtere-Villere. Fulltekst i vitenarkiv
• Kjørstad, Elise; Vandvik, Vigdis & Hessen, Dag Olav (2023). Forskere: Stadig ny bygging av hytter og veier passer ikke med målene om å bevare norsk natur. [Journal]. forskning.no. Fulltekst i vitenarkiv
• Halvorsen, Rune & Bryn, Anders (2023). Hvorfor mangler naturkartlegging tillit? Fulltekst i vitenarkiv
• Demeaux, Morgane; Vandvik, Vigdis; Rechsteiner, Aud Helen Halbritter & Kardol, Paul (2023). Plant functional groups mediate climate effects on mesofauna abundance and community composition. Fulltekst i vitenarkiv Vis sammendrag

  Climate change alters both plant and soil communities, and interactions in the plant-soil food web. These changes pose threats to biodiversity and key ecosystem processes and functions, such as carbon and nutrient cycling, as well as ecosystem productivity. Mesofauna take part of the organic matter decomposition in different ways and the structure and composition of these communities will depend on the type of food resources available in the soil. They not only decompose the organic matter, but are also releasing nutrients, fixing carbon, and/or feeding on each other. The climate affects these soil organisms both directly and indirectly, by shifting plant composition and modifying the food web interactions that govern soil ecosystem functioning. Therefore, understanding climate impact on the soil functioning, on the organisms involved in the soil food web, and on their interactions, is of major importance in the context of global warming. Here, we are assessing and disentangling the direct effects of climate from the indirect effects, mediated through biotic interactions, on the soil functioning studying soil nematodes and microarthropods abundance and feeding group composition. We use a macro-ecological experimental approach across factorial broad-scale temperature and precipitation gradients in Norway associated with a plant functional group removal experiment. Climate impact on plant functional group composition will indirectly affect the soil food web and thus we hypothesize that it could counter the direct effects of climate on the soil food web.

• Heiberg, Hanne; Kuya, Elinah Khasandi; Hanssen-Bauer, Inger & Mayer, Stephanie (2023). Rain, sleet and snow under global warming at Norwegian tourist destinations. Fulltekst i vitenarkiv
• Øystese, Kirsten; Vandvik, Vigdis; Mjøs, Aksel & Skancke, Martin (2023). Krisenes kamp. [Internet]. Klimafestvalen Varmere-Våtere-Villere. Fulltekst i vitenarkiv
• Vandvik, Vigdis (2023). Naturkrisa. Hva består den i? Hvorfor er den her? Hva kan gjøres? Fulltekst i vitenarkiv
• Kjørstad, Elise & Vandvik, Vigdis (2023). Slik planlegger verden å stoppe tapet av natur frem mot 2030. [Journal]. forskning.no. Fulltekst i vitenarkiv
• Engeland, Kolbjørn; Erlandsen, Helene B.; Gelati, Emiliano; Huang, Shaochun; Narayanappa, Devaraju & Pirk, Norbert [Vis alle 10 forfattere av denne artikkelen] (2023). Intercomparison of local evapotranspiration estimates at high latitudes. Fulltekst i vitenarkiv
• Stava, Eline Taule; Grape, Victoria H.; Geange, Sonya Rita; Demeaux, Morgane & Vandvik, Vigdis (2023). Good neighbors: Bryophytes’ role as water regulators in alpine grasslands. Fulltekst i vitenarkiv Vis sammendrag

  Our understanding of bryophytes’ role in ecosystems points to important functions in hydrology. However, data on bryophytes’ traits related to hydrology have been absent from or limited in climate and ecosystem studies. Certain morphological traits allow bryophytes to hold a lot of water relative to other plant functional groups. This gives them an important role in the ecosystem by regulating soil moisture and temperature. Water holding capacity (WHC) in bryophytes may be context dependent, with variation in direct factors such as temperature and precipitation and indirect effects of biotic interactions. To investigate these factors’ influence on WHC, we harvested bryophytes from The Vestland Climate Grid. This unique experimental grid consists of 12 alpine grassland sites in a climate grid of three levels of mean summer temperature (7.5, 9.5, and 12.5°C) and four levels of mean annual precipitation (600, 1200, 2000, and 2700mm). Total bryophyte community biomass was harvested from plots where graminoids and forbs have been removed annually since 2015 (GF) and from control plots (C). We conducted a laboratory experiment to measure WHC on these biomass samples. Preliminary results from the GF plots indicate that there is less variation in WHC across the precipitation gradient in the alpine bryophyte communities compared to that of their sub-alpine and boreal equivalents. Insights from this project will develop our understanding of these organisms’ role in climate regulation and biotic interactions. In particular, our work will contribute to improved representation of bryophytes and hydrological processes within land surface models, resulting in more accurate predictions of future climate-vegetation interactions in high-latitude systems.

• Althuizen, Inge; Jaroszynska, Francesca Orinda Holl; Halbritter, Aud Helen; Klanderud, Kari; Lee, Hanna & Telford, Richard James [Vis alle 7 forfattere av denne artikkelen] (2023). Keeping it cool - How mosses regulate soil microclimate. Fulltekst i vitenarkiv
• Vandvik, Vigdis (2023). Det kommunale selvstyret: Svarteper eller trumf for naturen? [Internet]. BOBcast. Fulltekst i vitenarkiv
• Falk, Stefanie; Vollsnes, Ane Victoria; Eriksen, Aud Berglen; Emberson, Lisa D.; O’Neill, Connie & Stordal, Frode [Vis alle 7 forfattere av denne artikkelen] (2023). Modelling the effects of ozone pollution on coniferous and deciduous forests. Fulltekst i vitenarkiv
• Bjerke, Jarle W.; Tallaksen, Lena M.; Stordal, Frode & Yilmaz, Yeliz A. (2023). EMERALD Open Science Day - Summary of Group Discussions. Fulltekst i vitenarkiv Vis sammendrag

  Group discussions, key questions: How to move from single discipline to multidisciplinary studies? Which processes are missing in terms of plant-climate interactions for improving models?

• Bryn, Anders (2023). The history of east-central Oslo. Fulltekst i vitenarkiv
• Bryn, Anders (2023). Natur i endring - hva skjer med den norske naturen? Fulltekst i vitenarkiv
• Rosnes, Oddbjørn Nils & Vandvik, Vigdis (2023). Forskar på den naturen ingen av oss ser - men som alt liv er er avhengig av. [Journal]. Avisa Nordhordland. Fulltekst i vitenarkiv
• Vandvik, Vigdis (2023). The nature crisis – a crash course. Fulltekst i vitenarkiv
• Vandvik, Vigdis (2023). Målkonflikter – å sette pris på naturen. Fulltekst i vitenarkiv
• Bryn, Anders (2023). Rødt kjøtt - bedre enn sitt rykte? Fulltekst i vitenarkiv
• Vandvik, Vigdis (2023). Forvaltning av natur for fremtiden. Fulltekst i vitenarkiv
• Kjørstad, Elise & Vandvik, Vigdis (2023). Naturavtalens betydning for Norge. [Journal]. forskning.no. Fulltekst i vitenarkiv
• Vandvik, Vigdis (2023). Gjør og sisik, trost og … elg? [Journal]. Morgenbladet. Fulltekst i vitenarkiv
• Vandvik, Vigdis (2023). Biologens blikk på bærekraft i kommunen. Fulltekst i vitenarkiv
• Vandvik, Vigdis; Sørheim, Maja Dineh; Skrindo, Astrid Brekke; Løken, Anders Magnus & Juel, Tone Margrethe Karlander (2023). Naturavtalen - hvordan ta vare på "hverdagsnaturen"? [Internet]. Tekna. Fulltekst i vitenarkiv
• Bjerke, Jarle W. & Tømmervik, Hans (2023). Synergies and trade-offs between provisioning and climate-regulating ecosystem services from reindeer herding areas. Fulltekst i vitenarkiv
• Bjerke, Jarle W. (2023). Klimaet i Norge nå og i framtiden - effekter på vegetasjon og reinbeiter. Fulltekst i vitenarkiv
• Vandvik, Vigdis (2023). Hvorfor fokusere mer på hverdagsnaturen? Fulltekst i vitenarkiv
• Bryn, Anders (2023). Ståan til Norsk skog. [Radio]. NRK Sommeråpent. Fulltekst i vitenarkiv Vis sammendrag

  15 minutters radiointervju med Tande-P på NRK P1, Sommeråpent, om tilstanden i Norsk skog.

• Bjerke, Jarle Werner & Finne, Eirik Aasmo (2023). Variasjon i albedo og andre karakteristikker av vegetasjon i åpne og nordlige økosystemer: rollen til lav og moser. Fulltekst i vitenarkiv
• Bryn, Anders; Brynildsrud, Katrine Marie; Horvath, Peter; Keetz, Lasse Torben; Lieungh, Eva & Naas, Adam Eindride [Vis alle 9 forfattere av denne artikkelen] (2023). “Ground-truth" from field-based ecosystem mapping. Fulltekst i vitenarkiv
• Bright, Ryan M. (2023). Carbon in Norwegian Forests: Historical developments, recent trends, and future outlooks. Fulltekst i vitenarkiv
• Bryn, Anders (2023). Natur i endring. Fulltekst i vitenarkiv
• Vandvik, Vigdis (2023). Naturkrisen og naturavtalen. Fulltekst i vitenarkiv
• Vandvik, Vigdis (2023). Naturmangfold og økosystemer – det må vi vel lenger ut på landet med? Fulltekst i vitenarkiv
• Myrtveit, Aase Cathrine; Vandvik, Vigdis & Vetlesen, Arne Johan (2023). Verdibørsen live - drøfter vårt natursyn. [Radio]. NRK. Fulltekst i vitenarkiv
• Vatne, Astrid; Vollsnes, Ane Victoria; Pirk, Norbert & Tallaksen, Lena M. (2023). Drought effects on dwarf birch leaves. Fulltekst i vitenarkiv
• Lieungh, Eva; Yilmaz, Yeliz; Tang, Hui; Keetz, Lasse Torben; Olsen, Siri Lie & Gya, Ragnhild [Vis alle 11 forfattere av denne artikkelen] (2023). Complementary field and modelling experiments: alpine vegetation under climate warming. Fulltekst i vitenarkiv
• Bryn, Anders (2023). Slik endres Norge. [Journal]. VG. Fulltekst i vitenarkiv
• Engeland, Kolbjørn; Aas, Kjetil Schanke; Erlandsen, Helene Birkelund; Gelati, Emiliano; Huang, Shaochun & Narayanappa, Devaraju [Vis alle 11 forfattere av denne artikkelen] (2022). LATICE MIP evapotranspiration – A model intercomparison project for evapotranspiration estimates at high latitudes. Fulltekst i vitenarkiv
• Parmentier, Frans-Jan W. (2022). Vinterskader: Hvordan påvirkes naturen av ekstremt vintervær og vintertørke? Fulltekst i vitenarkiv
• Bryn, Anders (2022). Historical lines and recent development at the Natural History Museum in Oslo. Fulltekst i vitenarkiv
• Bryn, Anders (2022). Utfordrer tregrensa: Se Oppdals kanskje høyestvoksende gran. [Journal]. https://www.opp.no/. Fulltekst i vitenarkiv
• Lieungh, Eva (2022). The Land Sites Platform makes CLM-FATES modelling easy. Now what? Fulltekst i vitenarkiv Vis sammendrag

  https://www.mn.uio.no/geo/english/research/projects/emerald/events/webinar/webinar-dec-2022.html

• Vandvik, Vigdis (2022). NRK nyhetene: Ekspertkommentar om tørke og effekter på matproduksjon i Europa. [TV]. NRK. Fulltekst i vitenarkiv
• Vandvik, Vigdis; Vetlesen, Arne Johan & Christensen, Tor Bjarne (2022). Hvorfor ødelegger vi naturen? [Journal]. Naturvernforbundet. Fulltekst i vitenarkiv
• Vandvik, Vigdis (2022). Klima- og naturkriser må løses sammen. Fulltekst i vitenarkiv
• Bjerke, Jarle W. & Steen, Kristian Wollen (2022). Store matter med reinlav kjøler ned klimaet. [Journal]. Nationen. Fulltekst i vitenarkiv
• Torgersen, Eivind; Vatne, Astrid & Vollsnes, Ane Victoria (2022). Planter er ikke bare passive mottakere av klimaendringer. [Journal]. Titan.uio.no. Fulltekst i vitenarkiv
• Vollsnes, Ane Victoria; Bryn, Anders & Stordal, Frode (2022). Fotosyntesen redder ikke klimaet. s. 19–19. Fulltekst i vitenarkiv Vis sammendrag

  Gjennom fotosyntesen tar plantene opp mye av de menneskeskapte klimagassutslippene. Tørke, brann, insektutbrudd og vindfall skaper imidlertid problemer for økosystemenes opptak og lagring av karbon.

• Tang, Hui; Aas, Kjetil Schanke; Althuizen, Inge; Geange, Sonya Rita; Berntsen, Terje Koren & Vandvik, Vigdis (2022). Update on the implementation of moss in CTSM-FATES. Fulltekst i vitenarkiv
• Aas, Kjetil Schanke; Lambert, Marius; Tang, Hui; Althuizen, Inge; Berntsen, Terje Koren & Fisher, Rosie [Vis alle 11 forfattere av denne artikkelen] (2022). Recent high-latitude vegetation developments in CLM-FATES. Fulltekst i vitenarkiv
• Finne, Eirik Aasmo; Tallaksen, Lena M.; Stordal, Frode & Bjerke, Jarle W. (2022). Effects of winter warming events on vegetation ecophysiology on a low-alpine ridge. Fulltekst i vitenarkiv
• Bryn, Anders (2022). Arealkonflikter - trender, utvikling og påvirkning. Fulltekst i vitenarkiv
• Yilmaz, Yeliz A.; Aalstad, Kristoffer; Filhol, Simon; Gascoin, Simon; Pirk, Norbert & Remmers, Janneke [Vis alle 8 forfattere av denne artikkelen] (2022). Evaluating modeled snow cover dynamics over Fennoscandia using Earth observations. Fulltekst i vitenarkiv Vis sammendrag

  The snow cover is an essential part of the climate system in cold regions through its effects on the terrestrial water, energy, and carbon balance. Due to the high spatiotemporal variability of snow, it is challenging to resolve snow cover dynamics in models. Thus, our ability to improve the representation of these dynamics in Earth System Models (ESMs) leans heavily on the accuracy and representativeness of the observational data sets used for model evaluation. The big picture provided by the long-term climate data record from satellites helps us to monitor changes in land cover over large areas. At the same time, rapidly developing drone and terrestrial imaging technology provides higher resolution information over specific areas. This complimentary information from spaceborne, airborne, and terrestrial Earth observations is invaluable for better understanding the complex processes in the climate system. In our work, we are currently exploiting estimates of snow-covered area from different optical sensors onboard polar orbiting satellites that are imaging the Nordic region. Drone and terrestrial images are being explored as a source of validation and calibration data for the satellite products.  Having representative snow cover maps enables us to better evaluate the terrestrial component of the Norwegian Earth System Model (NorESM), namely the Community Land Model (CLM5). With a focus on snow processes, we are conducting an analysis using satellite-based estimates of snow-covered area (MODIS, Sentinel-2, and Landsat 8), snow simulations from CLM5, snow variables from several climate reanalyses (ERA5, ERA5-Land, and MERRA-2), and in-situ data from eddy covariance stations (LATICE flux sites). Two offline CLM5 simulations are conducted with different atmospheric forcing, namely the default data set (GSWP3) and ERA5. We are investigating trends in the snow cover phenology, which we characterize using snow cover duration, first and last days of the snow cover, and consecutive snow cover days for each snow season over the last two decades. This work illuminates a path to integrate Earth observations with Earth system modeling in cold environments to both identify and constrain sources of uncertainty. Acknowledgement: This ongoing study is supported by the LATICE (Land-ATmosphere Interactions in Cold Environments) strategic research initiative funded by the University of Oslo, and the project EMERALD (294948) funded by the Research Council of Norway.

• Vandvik, Vigdis (2022). Naturkrisen – hva den er og hvordan vi løser den? Fulltekst i vitenarkiv
• Henmo, Jonas Bergvall & Vandvik, Vigdis (2022). Økolog etterspør nye grep for å stanse naturkrisa: VIL SETTE PRIS PÅ NATUREN. [Journal]. Klassekampen. Fulltekst i vitenarkiv
• Ursin, Lars & Vandvik, Vigdis (2022). Skal vi fikse klimaet, må vi spille på lag med naturen. [Journal]. Energy og Klima <2C. Fulltekst i vitenarkiv
• Bryn, Anders (2022). Flere trær i fjellet gjør det varmere: – Ikke utelukkende positivt med trær. [Internet]. www.nrk.no. Fulltekst i vitenarkiv
• Vandvik, Vigdis (2022). Skal vi fikse klimaet, må vi spille på lag med naturen. Energi og Klima : Norsk klimastiftelses nettmagasin. Fulltekst i vitenarkiv
• Bryn, Anders (2022). Willy (75) svinger saga for å rydde fram turistperle. [Internet]. www.nrk.no. Fulltekst i vitenarkiv
• Bryn, Anders (2022). Tree- and forest line dynamics in Norway: causes and consequences. Fulltekst i vitenarkiv
• Vandvik, Vigdis (2022). Å spå om tørke. [Journal]. Morgenbladet forskningsspalte. Fulltekst i vitenarkiv
• Bryn, Anders (2022). Utmark, beiting og klima. Fulltekst i vitenarkiv
• Vandvik, Vigdis; Seglsten, Liv-Hege & Langehaug, Helene R. (2022). Trilogien om Vindkraft 1 – klima, natur og energi. [Radio]. GreenPod. Fulltekst i vitenarkiv
• Lambert, Marius S. A.; Tang, Hui; Aas, Kjetil Schanke; Stordal, Frode; Fisher, Rosie & Bjerke, Jarle W. [Vis alle 7 forfattere av denne artikkelen] (2022). Towards realistic plant hydraulics and frost damage in the Arctic-Boreal Zone by modelling cold acclimation in CTSM5-Fates (hydro). Fulltekst i vitenarkiv
• Bryn, Anders; Vollsnes, Ane Victoria & Stordal, Frode (2022). Skogen utfordres i nytt klima. Nationen. ISSN 0805-3782. s. 20–20. Fulltekst i vitenarkiv Vis sammendrag

  Politikk som skal være grønn og klimavennlig kan ikke lene seg for kraftig på de grønne økosystemene. Eller satse på at de kan endres til vår fordel. Det er for risikabelt.

• Zhao, Junbin; Lange, Holger; Meissner, Helge Rainer & Bright, Ryan M. (2022). Heat Field Deformation (HFD) vs Linear Heat Balance (LHB): A critical comparison of two sap flow methods based on the same instrumentation. EGU General Assembly. Fulltekst i vitenarkiv Vis sammendrag

  As a way to estimate evapotranspiration (ET), Heat Field Deformation (HFD) is a widely used method to measure sap flow of trees based on empirical relationships between heat transfer within tree stems and the sap flow rates. As an alternative, the Linear Heat Balance (LHB) method implements the same instrumental configuration as HFD but calculates the sap flow rates using analytical equations that are derived from fundamental conduction-convection heat transfer equations.

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