MSc thesis: Two projects on Ecosystem Resilience

Background Ecosystems can have multiple alternative stable states. When ecosystems are shifted from their current stable state by a disturbance, they either recover back or transition into a different stable state. We aim to estimate stable states and their proprieties which can be used to predict responses of ecosystems to disturbances. To do so, we (the ECoMAP team) developed a multinomial regression model. Below are two potential topics for theses which use and validate this model:   1. How well does snapshot data predict ecosystem resilience? Snapshot data has been used for estimation of ecosystem resilience. This is a powerful approach since it enables to estimate future dynamics of a system (based on knowledge of its stable states and their proprieties) from present data. Although it is well theoretically based, the approach has not been systematically tested. This project aims to set a solid basis for this area of research by testing the potential of snapshot data for estimation of ecosystem resilience and its limitations. Snapshot data from a time-series (e.g., the Normalized Difference Vegetation Index, NDVI) will be taken and used to estimate stable states along climatic gradients using the multinomial model. Predicted resilience of individual ecosystems will be contrasted with observed changes within the time-series.   2. Is ecosystem resilience scale dependent? In studies of stable states and their resilience, it is often assumed that the results are not sensitive to used scale. However, on different scales, results of different processes can be visible, so this assumption is likely violated. This project will use data with different aggregation to explore the effects of scale on estimation of stable states of ecosystems. It will describe how stable states and their proprieties change with scale. Fine scale (satellite) data will be used to estimate stable states with different degree of data aggregation. Change in stable states and their proprieties will be assessed along the aggregation gradient.     Both projects are macroecological. They involve work with large spatial datasets, meaning you will gain vaulable experience experience with global data sources, data manipulation, and postprocessing of outputs of statistical modelling. The model is implemented in NIMBLE, therefore you will even gain insights into the basics of Bayesian statistics. Finally, both projects have great potential to result into scientific publication. Prerequisites Background in (macro)ecology Programming in R Basic knowledge of statistics Contact information: Does this sound interesting? Would you like to know more, or apply for this project? Contact: Adam Klimes (adam.klimes@uib.no) and Alistair Seddon (alistair.seddon@uib.no)

MSc thesis: NEMALearn, a tool to sort nematodes into feeding groups using Machine Learning

Background Nematodes are omnipresent in almost every ecosystem, even under harsh environmental conditions, and play important roles in soil processes, contributing to the provision of key ecosystem services such as nutrient cycling (Mekonen, Petros, and Hailemariam 2017). Nematodes alone are responsible for 2,2% of global carbon emission from the soil  (van den Hoogen et al. 2019), meaning the impact of climate change on these organisms needs to be considered for future climate scenarios. Because nematodes are such important part of natural ecosystems, the FUNDER project will focus on how their functional role, associated with their trophic position in the soil food web, change with climate. Nematode trophic classification is based on feeding groups. However, identifying and counting nematodes is time consuming, even if nematodes are identified to the family level. Finding efficient and automated tools for nematode identification will not only be faster, but also cheaper, and more precise, allowing us to process more samples, analyze more data and, hence, get a better understanding of the complex ecosystem processes we are studying. Machine learning has received increasing interest in the last two decades thanks to both increasing datasets and easier access to computing power (Krizhevsky, Sutskever, and Hinton 2017). Deep learning, and specifically Convolutional Neural Networks (CNNs), a branch of machine learning that uses internal hidden layers and convolutional layers, has proven to be very efficient for classifying images and has already been used in various fields of study. So far, only a few recent studies have been using CNNs for the identification of nematodes, but  the initial results are encouraging (Bogale, Baniya, and DiGennaro 2020; Thevenoux et al. 2021). The FUNDER project Climate change alters 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, and ecosystem productivity. The FUNDER project assesses and disentangles the direct effects of climate from the indirect effects, mediated through biotic interactions, on the diversity and functioning of the plant−soil food web. We use a macro-ecological experimental approach to quantify the impacts of vegetation diversity on interactions and ecosystem functioning across factorial broad-scale temperature and precipitation gradients in Norway. The objectives are to disentangle direct and indirect climate impacts on plants, soil nematodes and microarthropods, and microbes, and ecosystem processes. We aim to better understand landscape variation and whole-ecosystem consequences of indirect climate impacts as well as climate feedbacks of the plant-soil food web. Thesis proposal This MSc thesis will be conducted as part of the FUNDER project, where the MSc student will have responsibility to gather available datasets of nematode images (Lu et al. 2021) and complete the dataset through the collection of new images of individuals using a microscope in order to train the model. The successful candidate will classify these images from a newly constructed dataset into nematodes feeding groups. Using previous CNN work on nematode recognition and online code (Lu et al. 2021), the MSc student will perform training of a CNN with varying parameters (size and number of neuron layers in the network) and find the best parameters to achieve maximum accuracy in classifying images. The MSc student will have the opportunity to participate to the fieldwork campaign (if desired). The trained CNN will be applied on the samples collected. The collected new images will feed a new dataset that would be published, helping the global effort of identifying nematodes. Research objectives Create a machine learning tool to identify nematodes at the feeding level: training a CNN and make the CNN available for future research Identify a large number of soil nematode samples collected in the summer fieldwork 2022 for the FUNDER project with the CNN While identifying, collect, classify and publish new images of nematodes depending on the feeding group, and make this image dataset available on GitHub and OSF (Center for Open Science) You will be part of a dynamic research team, gather experience in scientific approach and have a cross disciplinary approach for the development of promising identification techniques. Tasks Labwork: collect images Programming work: build the CNN Participate to the fieldwork in August (optional) Data management, reproducibility and Open Science practice Share your results: write a thesis which can be published as a scientific paper and present your work in national/international conferences Candidate requirement Programming and machine learning background Lab skills (microscope) Interest for ecology and soil organisms Scientific writing skill Team spirit Practical information The project is funded through research grants Date: From May 2022 to October 2022 (possibility to shift the date if necessary) Place of work: University of Bergen, Norway Supervisors: Florian Muthreich (Post-Doc at UiB who worked on pollen identification using CNN (Muthreich 2021)), Morgane Demeaux (PhD FUNDER), and Vigdis Vandvik (leader of FUNDER). If you are interested send your CV and motivation letter to morgane.demeaux@uib.no.   References Afuye, G. A., A. M. Kalumba, and I. R. Orimoloye. 2021. ‘Characterisation of Vegetation Response to Climate Change: A Review’. Sustainability 13 (13): 7265. https://doi.org/10.3390/su13137265. Althuizen IHJ, Lee H, Sarneel J & Vandvik V. 2018. Long-term climate regime modulates the impact of short-term climate variability on decomposition in alpine grassland soils. Ecosystems 21: 1580-1592. doi: 10.1007/s10021-018-0241-5 Bogale, M., A. Baniya, and P. DiGennaro. 2020. “Nematode Identification Techniques and Recent Advances.” Plants (Basel, Switzerland) 9 (10): E1260. https://doi.org/10.3390/plants9101260. Engemann, K., B. Sandel, B. J. Enquist, P. M. Jørgensen, N. Kraft, A. Marcuse-Kubitza, B. McGill, et al. 2016. ‘Patterns and Drivers of Plant Functional Group Dominance across the Western Hemisphere: A Macroecological Re-Assessment Based on a Massive Botanical Dataset’. Botanical Journal of the Linnean Society 180 (2): 141–60. https://doi.org/10.1111/boj.12362. Hoogen, J. van den, S. Geisen, D. Routh, H. Ferris, W. Traunspurger, David A. Wardle, Ron G. M. de Goede, et al. 2019. “Soil Nematode Abundance and Functional Group Composition at a Global Scale.” Nature 572 (7768): 194–98. https://doi.org/10.1038/s41586-019-1418-6. Jaroszynska, F. 2019. ‘Climate and Biotic Interactions – Drivers of Plant Community Structure and Ecosystem Functioning in Alpine Grasslands’. University of Bergen. Kelly, A. E., and M. […]

MSc thesis: Effects of global change on seedlings in alpine grasslands

Project background Alpine ecosystems provide important ecosystem functions and services such as biodiversity, clean water, grazing pastures and carbon storage. Anthropogenic global change is now threatening alpine ecosystems and the functions it provides for nature and people. In the THREE-D project we study how three global change drivers, including warmer climate, nitrogen deposition and grazing affect alpine grasslands in Norway and China. Warmer climate and nitrogen addition, generally have a negative impact on biodiversity and ecosystem functions, such as carbon cycling. However, grazing at an intermediate level, has the potential to mitigate these negative impacts. To investigate the impact of these global change drivers, we use a large-scale, replicated field experiment, where we transplant plant communities to lower elevation to simulate a warmer climate crossed with nitrogen addition and different levels of grazing. We collect data on plant productivity, plant species composition, decomposition, and soil carbon fluxes to study their response to global change. Thesis proposal Question: How does a warmer climate, nitrogen addition and grazing affect seedling survival in alpine grasslands? Methods: Seedling recruitment and survival are important for the persistence and dispersal of plant populations and communities. Seedling survival has so far not been recorded in the THREE-D experiment. As a Msc student on this project you will record seedling emergence and survival over one growing season in the THREE-D experiment. Each seedling will be marked with a toothpick in spring and followed over several weeks. Opportunities As a MSc student working within the THREE-D project, you will: do field and lab work, and learn how to design and conduct ecological experiments, identify and measure plants, manage and analyze ecological data, write it up as a thesis, and present your work in oral presentations within the team and at conferences. be part of the ‘Between The Fjords’ lab group activities be part of a large collaborative international research project, where you will participate in project meetings and workshops online and in person.  Some specific projects are suggested on these pages. If you have other suggestions, don’t be afraid to contact us and ask! Contact information Aud Halbritter: aud.halbritter@uib.no

MSc thesis: Global change effects on soil decomposition and carbon in alpine grasslands

Project background Alpine ecosystems provide important ecosystem functions and services such as biodiversity, clean water, grazing pastures and carbon storage. Anthropogenic global change is now threatening alpine ecosystems and the functions it provides for nature and people. In the THREE-D project we study how three global change drivers, including warmer climate, nitrogen deposition and grazing affect alpine grasslands in Norway and China. Warmer climate and nitrogen addition, generally have a negative impact on biodiversity and ecosystem functions, such as carbon cycling. However, grazing at an intermediate level, has the potential to mitigate these negative impacts. To investigate the impact of these global change drivers, we use a large-scale, replicated field experiment, where we transplant plant communities to lower elevation to simulate a warmer climate crossed with nitrogen addition and different levels of grazing. We collect data on plant productivity, plant species composition, decomposition, and soil carbon fluxes to study their response to global change. Thesis proposal Question: How does global change impact decomposition and soil carbon stocks in alpine grasslands? Methods: Alpine soils store a large amount of carbon because processes such as respiration and decomposition are slow. It is therefore important to understand how the processes related to the carbon storage (decomposition, root growth) respond to global change. In spring 2021, we installed tea bags to measure decomposition rate and root ingrowth cores to quantify the root growth of vascular plants in the THREE-D experiment. We expect that warming and nitrogen addition will accelerate root production, while grazing can either repress or promote root growth. As a Msc student on this project you will collect the tea bags and root ingrowth cores in the field and analyse them in the lab. There will be opportunities to measure different traits like weight, specific root length etc. from the belowground biomass. Opportunities As a MSc student working within the THREE-D project, you will: do field and lab work, and learn how to design and conduct ecological experiments, identify and measure plants, manage and analyze ecological data, write it up as a thesis, and present your work in oral presentations within the team and at conferences. be part of the ‘Between The Fjords’ lab group activities be part of a large collaborative international research project, where you will participate in project meetings and workshops online and in person.  Some specific projects are suggested on these pages. If you have other suggestions, don’t be afraid to contact us and ask! Contact information Aud Halbritter: aud.halbritter@uib.no

MSc thesis: Plant response to a warmer climate, nitrogen deposition and grazing

Project background Alpine ecosystems provide important ecosystem functions and services such as biodiversity, clean water, grazing pastures and carbon storage. Anthropogenic global change is now threatening alpine ecosystems and the functions it provides for nature and people. In the THREE-D project we study how three global change drivers, including warmer climate, nitrogen deposition and grazing affect alpine grasslands in Norway and China. Warmer climate and nitrogen addition, generally have a negative impact on biodiversity and ecosystem functions, such as carbon cycling. However, grazing at an intermediate level, has the potential to mitigate these negative impacts. To investigate the impact of these global change drivers, we use a large-scale, replicated field experiment, where we transplant plant communities to lower elevation to simulate a warmer climate crossed with nitrogen addition and different levels of grazing. We collect data on plant productivity, plant species composition, decomposition, and soil carbon fluxes to study their response to global change. Thesis proposal Question: How does plant biomass/productivity and plant functional groups respond to a warmer climate, nitrogen deposition and grazing? Methods: Aboveground biomass has been harvested in the THREE-D experiment since 2019 with the goal to better understand how the single and combined effects of warmer climate, nitrogen addition and grazing impact biomass. As an Msc student on this project you will collect aboveground biomass in the final year of the THREE-D project (after 4 years of treatment). You will then sort the biomass into plant functional groups (graminoids, forbs, legumes, shrubs, bryophytes, lichen and litter), dry and weigh it. You will have access to the biomass data from the whole project period and be able to disentangle how each global change driver alone and in combination with other drivers affect aboveground biomass. Opportunities As a MSc student working within the THREE-D project, you will: do field and lab work, and learn how to design and conduct ecological experiments, identify and measure plants, manage and analyze ecological data, write it up as a thesis, and present your work in oral presentations within the team and at conferences. be part of the ‘Between The Fjords’ lab group activities be part of a large collaborative international research project, where you will participate in project meetings and workshops online and in person.  Some specific projects are suggested on these pages. If you have other suggestions, don’t be afraid to contact us and ask! Contact information Aud Halbritter: aud.halbritter@uib.no

MSc thesis: The role of bryophytes in regulating carbon, energy and water fluxes across climatic gradients

Background Alpine grasslands are vulnerable to climate change, and are currently changing rapidly in both plant functional group dominance (Engemann et al. 2016) and species distributions (Kelly and Goulden 2008). These biotic shifts contribute to indirect effect of climate change through influencing biotic interactions (Vandvik et al. 2020). Bryophytes are regulating soil temperature and moisture: they have an important role on soil micro-climate (Althuizen 2018) and consequently on soil processes such as litter decomposition (Petraglia et al. 2019), and soil function such as plant seedlings growth (Lett et al. 2017). New threats, such as climate change, will modify bryophyte species distribution through biotic and abiotic shifts. A recent study using a warming experiment showed that bryophytes may be the functional group the most impacted by climate warming ( van Zuijlen et al. 2021). Here, we would like to study how climate and plant composition influence bryophytes hydrological and thermal regulation properties to better anticipate future climate change impact. The collected data will also be used within large-scale climate models, where we are developing new approaches to representing the important role of moss and lichen in regulating fluxes of carbon, energy and water in the Norwegian Earth System model (NorESM) in order to improve representation of high-latitude ecosystems and their climate interactions. The FUNDER and EMERALD projects Climate change alters 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, and ecosystem productivity. The FUNDER project assesses and disentangles the direct effects of climate from the indirect effects, mediated through biotic interactions, on the diversity and functioning of the plant−soil food web. We use a macro-ecological experimental approach to quantify the impacts of vegetation diversity on interactions and ecosystem functioning across factorial broad-scale temperature and precipitation gradients in western Norway. The objectives are to disentangle direct and indirect climate impacts on plants, soil nematodes and microarthropods, and microbes, and ecosystem processes. We aim to better understand landscape variation and whole-ecosystem consequences of indirect climate impacts as well as climate feedbacks of the plant-soil food web. EMERALD focuses on integrating data from field projects such as FUNDER into dynamic global vegetation models (CTSM-FATES), so as to better represent the role of vegetation-climate interactions in high-latitude ecosystems. MSc project This MSc thesis will be conducted as part of the FUNDER and EMERALD projects, where the MSc student will have responsibility for assessing key attributes of bryophyte communities across the FUNDER experimental sites. In addition to field-surveys of bryophyte communities and harvesting biomass across the climate grid (summer 2022), further lab-based opportunities include: investigating the impact of bryophytes on regulating hydrological processes through measuring the water holding capacity of bryophyte communities; assessing how the reflectance of bryophyte communities may shift according to their desiccation status or community composition; and how bryophytes moderate local thermal micro-climates. These characteristics can be used to in the EMERALD modelling to better predict how moss and lichen communities influence their surrounding microclimate environments, and how responses may vary depending upon the direct and indirect effects of climate. Potential research questions 1. How does the biodiversity and functioning of bryophytes in alpine grasslands vary along broad-scale climate gradients? 2. Are the responses of this plant functional group to climate influenced or modified by biotic interactions? You will be part of a dynamic research team, gather experience in scientific approach and have an amazing fieldwork experience in fjords and mountains in Western Norway. Tasks • Fieldwork collecting above-ground biomass • Lab work sorting bryophytes, weigh the biomass (fresh and dry), measuring water holding capacity, reflectance shifts and thermal properties of bryophytes • Data management, reproducibility and Open Science practices • Statistical analyses using R • Scientific communication skills: write a thesis which can be published as a scientific paper and presented in national/international conferences Candidate requirement • Global change ecology background • Interest for bryophytes ecology • Scientific rigor on the field and in the lab • Statistical and data management skills • Scientific writing skill • Team spirit • Enjoy hiking in mountains and being outside under both sunny and rainy weather Practical information • Date: From July 2022 to December 2022 • Place of work: University of Bergen, Norway • Supervisors: Sonya Geange, Morgane Demeaux and Vigdis Vandvik • Application: CV and motivation letter at morgane.demeaux@uib.no and Sonya.Geange@uib.no before 2nd of May 2022 References – Althuizen, I. 2018. ‘The Importance of Vegetation Functional Composition in Mediating Climate Change Impacts on Ecosystem Carbon Dynamics in Alpine Grasslands’. University of Bergen. – Engemann, K., B. Sandel, B. J. Enquist, P. M. Jørgensen, N. Kraft, A. Marcuse-Kubitza, B. McGill, et al. 2016. ‘Patterns and Drivers of Plant Functional Group Dominance across the Western Hemisphere: A Macroecological Re-Assessment Based on a Massive Botanical Dataset’. Botanical Journal of the Linnean Society 180 (2): 141–60. https://doi.org/10.1111/boj.12362. – Kelly, A. E., and M. L. Goulden. 2008. ‘Rapid Shifts in Plant Distribution with Recent Climate Change’. Proceedings of the National Academy of Sciences 105 (33): 11823–26. https://doi.org/10.1073/pnas.0802891105. – Lett, S., M.-C. Nilsson, D. A. Wardle, and E. Dorrepaal. 2017. ‘Bryophyte Traits Explain Climate-Warming Effects on Tree Seedling Establishment’. Journal of Ecology 105 (2): 496–506. https://doi.org/10.1111/1365-2745.12688. Petraglia, A., C. Cacciatori, S. Chelli, G. Fenu, G. Calderisi, Domenico Gargano, Thomas Abeli, Simone Orsenigo, and Michele Carbognani. 2019. ‘Litter Decomposition: Effects of Temperature Driven by Soil Moisture and Vegetation Type’. Plant and Soil 435 (1): 187–200. https://doi.org/10.1007/s11104-018-3889-x. – Vandvik, V., O. Skarpaas, K. Klanderud, R. J. Telford, A. H. Halbritter, and D. E. Goldberg. 2020. ‘Biotic Rescaling Reveals Importance of Species Interactions for Variation in Biodiversity Responses to Climate Change’. Proceedings of the National Academy of Sciences 117 (37): 22858–65. https://doi.org/10.1073/pnas.2003377117. – Zuijlen, K. van, K. Klanderud, O. S. Dahle, Å. Hasvik, M. S. Knutsen, Siri Lie Olsen, Snorre Sundsbø, and Johan Asplund. 2021. ‘Community-Level Functional Traits of Alpine Vascular Plants, Bryophytes, and Lichens after Long-Term Experimental Warming’. Arctic Science, April, 1–15. https://doi.org/10.1139/as-2020-0007.

MSc thesis: Plant community responses to the direct and indirect effects of climate in the Vestland Climate grid

Background Alpine grasslands are vulnerable to climate change, and are currently changing rapidly in both plant functional group dominance (1) and species distributions (2). These biotic shifts contribute to indirect effect of climate change through influencing biotic interactions (3,4). Indeed, research is still needed on the effect of climate on long-term vegetation dynamics (5). Our research group uses a macro-ecological experimental approach to quantify the impacts of climate and biotic interactions on biodiversity and ecosystem functioning of alpine grasslands across factorial broad-scale temperature and precipitation gradients in Norway (the Vestland climate Grid). For example, Althuizen et al. (2018) studied the impact of long-term climate regime on decomposition in alpine grassland soils (6). The FUNDER project Climate change alters not only plants, but also soil communities, and thus interactions across the plant-soil food web. These interlinked changes pose threats to biodiversity and key ecosystem processes and functions, such as carbon and nutrient cycling, and ecosystem productivity. The FunCab project, using a long-term plant functional group removal experiment (fully factorial removals of grasses, forbs and bryophytes, maintained since 2015) in semi-natural grassland replicated across the 12 sites of the Vestland Climate Grid, studied the direct and indirect impact of climate on plant communities. The new project, FUNDER, pursues the work done on FunCab integrating data of the belowground part in order to better understand the impact of climate on the plant-soil food web. The FUNDER project thus continues and expands this research to assess and disentangle the direct effects of climate from the indirect effects, mediated through biotic interactions, on the diversity and functioning of the plant−soil food web. The objectives are to disentangle direct and indirect climate impacts of three major plant functional types in grasslands – grasses, forbs and bryophytes – on plants, soil nematodes and microarthropods, and microbes, and ecosystem processes. We aim to better understand landscape variation and whole-ecosystem consequences of indirect climate impacts as well as climate feedbacks of the plant-soil food web. Thesis proposal This MSc thesis will be conducted as part of the FUNDER project, where the MSc student will have responsibility for assessing plant community responses to the direct and indirect effects of climate.  The successful candidate will continue a time-series of plant species composition once a year from 2015 to 2019 in the removal experiments described above. This will complete a unique dataset on the plant community composition in response to climate and plant functional group manipulation over 8 years. The MSc student will identify plant species during the last fieldwork campaign on this experiment before the destructive harvesting for soil sampling planned for the FUNDER project in 2022, which in collaboration with the work carried out by the rest of the FUNDER team will allow comparisons and linkages between plant, animal, and microbial responses. The MSc thesis will explore how the biomass, biodiversity and functional composition three plant functional groups in grasslands respond to changes in climate and biotic interactions. Research questions How does the biodiversity and functioning of grasses, forbs, and bryophytes in alpine grasslands vary along broad-scale climate gradients? Are the responses of these major plant functional groups to climate influenced or modified by biotic interactions among them? Is there a temporal shift in plant species composition and biotic interactions? You will be part of a dynamic research team, gather experience in scientific approach and have amazing fieldwork experience in fjords and mountains in Western Norway. Tasks 3-5 weeks of fieldwork, identifying species and analyzing plant community composition Data management, reproducibility and Open Science practice Statistical analyses using R Share your results: write a theisis which can be published as a scientific paper, and present your work in national/international conferences Candidate requirement Global change ecology background Plant species identification skills, knowledge of Norwegian flora is an advantage Statistical and data management skills Scientific writing skill Team spirit Enjoy hiking in mountains and being outside under both sunny and rainy weather Practical information The project is funded through research grants Start: July 2022 Place of work: University of Bergen Supervisor: Vigdis Vandvik and Morgane Demeaux. To apply, send your CV and motivation letter to morgane.demeaux@uib.no before 15th of May 2022.   References (1) Engemann, K., B. Sandel, B. J. Enquist, P. M. Jørgensen, N. Kraft, A. Marcuse-Kubitza, B. McGill, et al. 2016. ‘Patterns and Drivers of Plant Functional Group Dominance across the Western Hemisphere: A Macroecological Re-Assessment Based on a Massive Botanical Dataset’. Botanical Journal of the Linnean Society 180 (2): 141–60. https://doi.org/10.1111/boj.12362. (2) Kelly, A. E., and M. L. Goulden. 2008. ‘Rapid Shifts in Plant Distribution with Recent Climate Change’. Proceedings of the National Academy of Sciences 105 (33): 11823–26. https://doi.org/10.1073/pnas.0802891105. (3) Jaroszynska, F. 2019. ‘Climate and Biotic Interactions – Drivers of Plant Community Structure and Ecosystem Functioning in Alpine Grasslands’. University of Bergen. (4) Vandvik V, Klanderud K, Skarpaas O, Telford RJ, Halbritter AH & Goldberg DE. 2020. Biotic rescaling reveals importance of species interactions for variation in biodiversity responses to climate change. PNAS  17 (37): 22858-22865. doi: 10.1073/pnas.2003377117 (5) Afuye, G. A., A. M. Kalumba, and I. R. Orimoloye. 2021. ‘Characterisation of Vegetation Response to Climate Change: A Review’. Sustainability 13 (13): 7265. https://doi.org/10.3390/su13137265. (6) Althuizen IHJ, Lee H, Sarneel J & Vandvik V. 2018. Long-term climate regime modulates the impact of short-term climate variability on decomposition in alpine grassland soils. Ecosystems 21: 1580-1592. doi: 10.1007/s10021-018-0241-5

MSc thesis: Representing alpine ecosystems in the Norwegian Earth System Model

EMERALD is an interdisciplinary and nationally coordinated research project which aims to improve the representation of high latitude and alpine ecosystems, along with their climate interactions, in the Norwegian Earth System Model (NorESM). Here, we look to integrate empirical data from the projects already underway at UiB (for example SEEDCLIM, FunCAB, INCLINE) along with broader data synthesis ideas to improve our understanding and modelling of vegetation feedback processes. We have a couple of options available this year, see below. Supervisor: Sonya Geange Sonya.Geange@uib.no

MSc thesis: Establishment success of range-expanding species in a montane grassland

Project background As both native and exotic species shift their distributions in response to climate warming and through biological invasions, many expand their ranges across elevational gradients. This expansion results in the reassembly of ecological communities, which meditates the effects of climate warming on biodiversity and key ecosystem functions. RangeX is a multidisciplinary, replicated field and laboratory experiment being conducted in climatically and socio-ecologically contrasting regions (Switzerland, Norway, China, South Africa) that seeks to better understand these range shifts in mountain habitats. We focus on mountain ecosystems as an ideal model system to address our research questions. Mountains are themselves of crucial conservation value, as hotspots of biodiversity, refugia for biota threatened by climate warming, and as key global sources of water, food, and livelihoods, but are experiencing above-average rates of warming and increasing pressures from invasive species and development, making mountains priority areas for sustainability research. Experimental design RangeX field experiments comprise warming treatments, introduction and removal of key plant species, and intensive monitoring of soils, plants and pollinators across multiple elevations. By investigating novel biotic interactions both above and below ground, we aim to: (i) disentangle the drivers of range expansions; (ii) uncover the consequences of range-expanders on biodiversity and ecosystem functioning; and (iii) predict the extent and impacts of future range expansions. Location: montane and lowland grasslands near Voss, Norway. Thesis proposal Question: Can lowland grassland species successfully establish in a montane setting? Methods: Our current experimental setup looks at the drivers and impacts of range-expanding plants by monitoring vital rates and functional traits of transplanted seedlings of lowland species in a mountain valley. Yet, this doesn’t allow us to test whether these plants are able to establish themselves via seeds. This can be investigated with an in-situ germination experiment using seeds. Seeds of our ten focal species would be sown within our established plots, where we can document seed germination success as a response to various treatments (e.g., artificial warming using OTCs). Data on germination rates and seedling traits will be valuable in parsing factors that drive the success/failures of range-expanding plants. Opportunities As a MSc student working within the RangeX project, you will: • Do field work, and learn how to design and conduct ecological experiments, identify and measure plants and/or insect pollinators, manage and analyze ecological data, write it up as a thesis, and present your work in oral presentations within the team and at conferences. • Be part of the ‘Between The Fjords’ lab group activities • Be part of a large collaborative international research project, where you will participate in project meetings and workshops online and in person. • Get to know and work with a cross-disciplinary group of researchers at different career stages, and see how your work relates to work on different functional groups and trophic levels. • Be given opportunities to present your work at scientific conferences, and you will be supported in publishing your thesis as a scientific article. We have listed multiple thesis options on this website, but if you have other suggestions, don’t be afraid to contact us and ask! Contact information Nathan.Phinney@uib.no Vigdis.Vandvik@uib.no

MSc thesis: Impacts of range-expanding plants on pollinator interactions

Project background As both native and exotic species shift their distributions in response to climate warming and through biological invasions, many expand their ranges across elevational gradients. This expansion results in the reassembly of ecological communities, which meditates the effects of climate warming on biodiversity and key ecosystem functions. RangeX is a multidisciplinary, replicated field and laboratory experiment being conducted in climatically and socio-ecologically contrasting regions (Switzerland, Norway, China, South Africa) that seeks to better understand these range shifts in mountain habitats. We focus on mountain ecosystems as an ideal model system to address our research questions. Mountains are themselves of crucial conservation value, as hotspots of biodiversity, refugia for biota threatened by climate warming, and as key global sources of water, food, and livelihoods, but are experiencing above-average rates of warming and increasing pressures from invasive species and development, making mountains priority areas for sustainability research. Experimental design RangeX field experiments comprise warming treatments, introduction and removal of key plant species, and intensive monitoring of soils, plants and pollinators across multiple elevations. By investigating novel biotic interactions both above and below ground, we aim to: (i) disentangle the drivers of range expansions; (ii) uncover the consequences of range-expanders on biodiversity and ecosystem functioning; and (iii) predict the extent and impacts of future range expansions. Location: montane and lowland grasslands near Voss, Norway. Thesis proposal Question: Do range-expanding plant species disrupt plant-pollinator interactions? Methods: Quantify insect visitation rates of the planted focal range-expanding species and selected native plants in the background community using novel image-based methodology. Images will be collected every minute each day during the growing season using time lapse cameras mounted over flowering plants from bud burst to seed set. At each site, 24 cameras will record focal range-expanding species, and native plants with matched floral traits next to and away from the range-expanding species. Deep learning convolutional neural networks (CNNs) will be used to automatically extract the timing, location, and identity of flower visitors from the images. This will allow us to quantify the importance of visitation rates, and visitor identity and diversity, for seed set of both native and range-expanding plant species. Sweep netting, pan trapping, and direct observation will be used to confirm the identity of observed flower visitors and their status as pollinators. The machine learning models will be trained on a manually labelled subset of images at each site. The field methodology has already been tested at sites in Greenland and Denmark, the analysis pipelines have been developed, and the most appropriate CNN models have been identified. Opportunities As a MSc student working within the RangeX project, you will: • Do field work, and learn how to design and conduct ecological experiments, identify and measure plants and/or insect pollinators, manage and analyze ecological data, write it up as a thesis, and present your work in oral presentations within the team and at conferences. • Be part of the ‘Between The Fjords’ lab group activities • Be part of a large collaborative international research project, where you will participate in project meetings and workshops online and in person. • Get to know and work with a cross-disciplinary group of researchers at different career stages, and see how your work relates to work on different functional groups and trophic levels. • Be given opportunities to present your work at scientific conferences, and you will be supported in publishing your thesis as a scientific article. We have listed multiple thesis options on this website, but if you have other suggestions, don’t be afraid to contact us and ask! Contact information Nathan.Phinney@uib.no Vigdis.Vandvik@uib.no