22 February 2023 | 08:30 - 10:00 (GMT+1)
22 February 2023 | 10:30 - 12:00 (GMT+1)
Open Session - HYBRID
Room: Hörsaal 5
Session Conveners: Fredrik Dalerum (Spanish National Research Council, Spain)); Isabel C. Barrio (Agricultural University of Iceland, Iceland); Mats Björkman (University of Gothenburg, Sweden)
Terrestrial ecosystems are changing rapidly as a consequence of human activities, and climate change is arguably one of the most prominent anthropogenic disturbances currently occurring. Its impact on terrestrial ecosystems worldwide is one of the key threats to biodiversity and critical ecosystem services. Terrestrial arctic biodiversity requires special attention, as the Arctic is heating up much faster than other regions of the planet. Areas of climate extremes are further likely to see the most dramatic effects of climate alterations. The Arctic also holds endemic, cold-adapted species and provides important breeding grounds for long-distance migrators. Many species in the terrestrial Arctic are also important for indigenous cultures and hold both subsistence, cultural and recreational values. In this session we aim to synthesise current scientific and indigenous knowledge of the consequences of climate change for terrestrial arctic biodiversity. This session invites abstract submissions related to the consequences of climate change for terrestrial biodiversity in all organism groups and geographic areas in the Arctic.
Session 1: Biodiversity patterns and processes (08:30 - 10:00 GMT+1):
unfold_moreEnvironmental and anthropogenic factors co-shape plant species richness across the Western Siberian tundra
Vitalii Zemlianskii1; Natalia Koroleva; Philipp Brun2; Niklaus Zimmermann2; Ksenia Ermokhina; Olga Khitun; Gabriela Schaepman-Strub1
1University of Zurich; 2Swiss Federal Institute for Forest, Snow and Landscape Research
Western Siberia is one of the most important areas of economic activity North of the Arctic Circle. Tundra plant communities of the region are changing rapidly due to climate change, fossil fuel extraction and reindeer herding. We investigated the relative impact of environmental and anthropogenic factors on the plant species richness of the Western Siberian tundra using macroecological models. Our research is based on the Western Siberian part of the Russian Arctic Vegetation Archive (AVA-RUS, http://avarus.space), with ≈1500 geobotanical plots observed from 2005-2018. We used random forest (RF), gradient boosting machines (GBMs), generalized linear models (GLMs), and generalized additive models (GAMs) to estimate the community level species richness across the Western Siberian tundra, with climate, topography and human activity identified as main explanatory factors. We found that community-level species richness in the area does not follow the expected decrease with increasing latitude. Instead, we identified an increase in species richness from South-West to North-East. We found that the lowest species richness is associated with medium distance to infrastructure while neighboring and remote areas have relatively high species richness. By intersecting current nature protection areas with our species richness map, we document that areas with higher species richness are currently poorly protected.
unfold_moreWill climate warming and grazing affect the metabolome of an allelopathic evergreen shrub in a degraded tundra ecosystem?
Ingvild Ryde1; Ingibjörg Svala Jónsdóttir1; Elizabeth Heather Jakobsen Neilson2; Augustin Baussay2; Delphine Pottier2; Kari Anne Bråthen3
1University of Iceland; 2University of Copenhagen; 3The Arctic University of Norway
In the Anthropocene, loss of biodiversity is of major concern and our ability to restore biodiversity is increasingly asked for. Allelopathic effects by a few species that have increased in abundance might however inhibit the restoration of ecosystems. In Iceland, extensive land degradation from land use has lead to loss of biodiversity. One of the most abundant allelopathic species is Empetrum nigrum, which produces large quantities of secondary metabolites. Previous studies have documented allelopathic effects of E. nigrum in mainland Scandinavia. However, metabolic profiling of Icelandic E. nigrum has, to our knowledge, not been performed. Furthermore, the effects of warming and extensive grazing on the E. nigrum metabolome is unknown. This study also aims to improve our knowledge of how the E. nigrum metabolome is affected by climate change and grazing as this might impact its allelopathic capacities and thereby its effect on the restoration of ecosystems. E. nigrum leaves were collected from an International Tundra Experiment (ITEX) site in the subarctic highlands of Iceland including long-term (26 years) experimental warming plots (open-top-chambers) and grazing-exclusion plots (fence). Both targeted and untargeted liquid chromatography-mass spectrometry (LC-MS) approaches are used to assess treatment effects and the allelopathic capacities of E. nigrum. Preliminary results suggest an allelopathic effect of E. nigrum leaves on seed germination of a palatable grass species (bioassays) and the presence of known allelopathic compound, i.e., batatasin-III also in Icelandic E.nigrum populations.
unfold_moreBiodiversity and trophic interactions on fragmented peninsulas in the high Arctic
Fredrik Dalerum1; Johannes Måsviken2; Love Dalen2; Karin Noren2; Muzit Abrham2; Jordi Bartolomé Filella3; Anders Angerbjörn2; Nicolas Lecompte4; Patrícia Pečnerová5,
1Biodiversity Research Institute / Spanish National Research Council; 2Stockholm University; 3Universitat Autònoma de Barcelona; 4University of Moncton; 5University of Copenhagen
Anthropogenically-driven climate change is already shifting species distributions and transforming local community composition. Such alterations to species communities may have particularly large ecological consequences for Arctic environments, with High Arctic regions potentially forming climate refugia for arctic species with a warming climate. However, communities in such high Arctic climate refugia are likely to experience substantial fragmentation. Here we quantified the diversity of vascular plants, arthropods, and vertebrates on three fragmented peninsulas in some of the northernmost land areas on Earth, northern Greenland and Ellesmere Island. We further evaluated the evidence for community assembly processes for all organism groups on the three peninsulas and quantified the trophic interaction structures that may have been derived from these processes. We observed both biodiversity differences among peninsulas as well as various patterns of trait dispersion, which suggests regional variation in community assembly processes. Trophic interaction structures differed between predator-prey and herbivore-plant networks, with the former being more structured than the latter. We argue that our results will have strong ramifications for the ability to predict ecological responses to climate change in northern terrestrial ecosystems.
unfold_moreLatitudinal and environmental effects on the breeding phenology of a declining seabird
Alice Edney1; Tom Hart1; Mark Jessopp2; Matt Wood3; Ellie Owen4,
1University of Oxford; 2University College Cork; 3University of Gloucestershire; 4National Trust for Scotland
The timing of breeding plays a key role in determining species’ reproductive success, which depends on the match between the seasonal peak in food availability and nutritional requirements of growing young. However, changes in phenology are one of the most evident responses to rising global temperatures. Phenology of species occupying higher trophic levels, such as seabirds, may be less responsive to environmental change than those occupying lower trophic levels. This can make seabirds particularly sensitive to trophic mismatch and associated declines in breeding success. There is evidence to suggest that this effect is greater at higher latitudes, and so data is needed across species’ latitudinal ranges to assess which populations may be most threatened by a changing climate. We use data from the Zooniverse citizen science project, Seabird Watch, to investigate changes in the timing of breeding of a globally declining seabird, the Black-legged Kittiwake Rissa tridactyla. Time-lapse cameras collect images across the species’ North Atlantic range (including Svalbard, Greenland, Iceland, the Faroes, and the UK) and volunteers tag kittiwakes in these images. By extracting key phenological dates across multiple locations and years, we aim to show how breeding timing is influenced by latitude and environmental variables and how it could affect reproductive success, thereby informing our understanding of species’ responses to climate change. We highlight the value of cameras for population monitoring of declining species in remote areas, and of citizen science for processing large volumes of data, while also providing important science outreach.
unfold_moreHigh Arctic river ecosystems in a changing climate
Leopold Füreder1; John Edward Brittain2
1University of Innsbruck; 2Natural History Museum / University of Oslo
Arctic freshwater ecosystems are characterized by low temperatures, a short ice-free period, low productivity and low biodiversity, although recent work has demonstrated that in some terrestrial habitats a rich invertebrate fauna can be found. More recent research has emphasised the importance of water source and catchment characteristics in structuring the nature of Arctic and alpine freshwater streams. By characterising the structure and function of the benthic fauna in High Arctic streams on Svalbard, we aimed to elucidate the importance of water source and its relationship to inputs of organic matter and other nutrients into the streams. We found that the gradient of environmental harshness expressed by the contribution of different water sources and catchment characteristics determine organic matter availability, biodiversity and food-web structure. This will enable us to predict the effect of environmental impacts, including climate change, on these stream ecosystems.
Session 2: Tools for biodiversity measurements (10:30 - 12:00 GMT+1):
unfold_moreEye in the sky: The use of Unoccupied Aerial Systems to unveil reindeer grazing effect on shrubification in tundra mires
University of Eastern Finland
Earth Observation has become an essential tool to understand shrubification dynamics and monitor its impacts on the structures and functions of Arctic ecosystems. However, the fine scale of shrub expansion processes often renders them invisible or hazy under the eye of satellite sensors. On the other hand, the rapid growth of Unoccupied Aerial Systems and sensor capabilities opens new opportunities for mapping and monitoring. Here, we present a toolset of Unmanned Aerial Systems and Machine Learning algorithms that enables highly accurate monitoring of landcover change dynamics in the sub-arctic tundra. The study area is located in the Fennoscandian oroarctic tundra zone, between the Finnish-Norwegian border. In the mid 1950s, a reindeer fence was built along the border, thus separating two different reindeer grazing strategies. While reindeer graze only during winter in the Norwegian side, grazing occurs all year round in the Finnish side. We combined multispectral and photogrammetric data obtained from UAVs with an ensemble of machine learning algorithms to map the extent of woody shrubs, quantify their above-ground biomass, growth patterns and associated topsoil moisture at two wetlands across the Finnish-Norwegian border. The results show a clear expansion of willows in the Norwegian side of the border, associated to a lower reindeer grazing pressure. The high degree of accuracy obtained in the results unfolds new research prospects, such as the combination of fine-scale remote sensing with chamber and Eddy Covariance measurements to quantify the impact of land cover on the carbon and energy balance. The use of Unmanned Aerial Systems could also help unveil the complexity of greening and browning patterns in the Arctic.
unfold_moreStandardizing efforts to measure the effects of herbivore diversity in tundra ecosystems
Isabel C Barrio1; James Speed2; Kirsten Engeseth2; Timo Kumpula3; Elina Kaarlejärvi4; Eeva Soininen5; Hans Jørgen Skydt Andersen6; Rolf Blöcher; Mathilde Defourneaux1; Sørine Gerlich6; Toke Thomas Høye6; Ingibjörg Svala Jónsdóttir7; Tiina H M Kolari3; Johannes Lang8; Benoît Sittler9; Britta Steger1; Teemu Tahvanainen3; Tarmo A Virtanen4; Charlotte Wagner1
1Agricultural University of Iceland; 2Norwegian University of Science and Technology; 3University of Eastern Finland; 4University of Helsinki; 5UiT The Arctic University of Norway; 6Aarhus University; 7University of Iceland; 8Justus-Liebig Universität Giessen; 9University of Freiburg
Herbivore diversity influences the effects that herbivores have on ecosystems because herbivores differ in their habitat preferences, food choices and feeding styles. However, herbivore diversity is rarely addressed in ecological studies. This applies particularly to high latitude ecosystems, where rapid ongoing environmental changes are reshaping the structure and composition of herbivore communities. Large-scale, standardized observations and coordinated experiments can help understand the consequences of these changes to ecosystem functioning. Within the TUNDRAsalad project we are designing protocols for measuring the effects of herbivore diversity in tundra ecosystems in a standardized way. By experimentally excluding vertebrate herbivores of different sizes from different tundra habitats, we are investigating herbivore impacts on tundra plant communities and ecosystem functions. This experimental protocol is complemented by an observational protocol that measures herbivore diversity at a local scale at a larger number of sites across the tundra biome. These sampling protocols were tested in summer 2022, when three experimental sites and two observational sites were established. This presentation outlines the main study questions and hypotheses underlying the protocol design and preliminary results from the summer 2022 campaign, and invites researchers working in the tundra biome to join the study.
unfold_moreA new improved paper version of the Circumpolar Arctic Vegetation Map
Martha Raynolds1; D.A. (Skip) Walker1; Jana Peirce1
1University of Alaska Fairbanks
The first version of the Circumpolar Arctic Vegetation Map (CAVM) has been used as a base map for biodiversity and other studies in the Arctic. However, the relatively coarse resolution and vector format of the map were not compatible with raster data sets. We present a new version of the CAVM, building on the strengths of the original map, while providing a finer spatial resolution, raster format, and improved mapping. The new CAVM uses the legend (16 vegetation types), extent and projection of the original CAVM. In contrast to the original hand-drawn CAVM, the new map is based on unsupervised classifications of seventeen geographic/floristic sub-sections of the Arctic, using AVHRR and MODIS data (reflectance and NDVI) and elevation data. The Raster CAVM has more detailed mapping of water-bodies and mountainous areas, portrays coastal-inland gradients, and better reflects the heterogeneity of vegetation type distribution than the original CAVM. Accuracy assessment of random 1-km pixels interpreted from 6 Landsat scenes showed an average of 70 % accuracy, up from 39 % for the original CAVM. This improved mapping is important for quantifying existing and potential changes to land cover, a key environmental indicator for modeling and monitoring ecosystems. Digital versions of the final product are publicly available at www.geobotany.uaf.edu and at Mendeley Data, DOI: 10.17632/c4xj5rv6kv.1. Beautiful two-sided paper 90-cm x 90-cm color copies include the map and abbreviated legend on the front side side and detailed descriptions and photos of the map units, description of the mapping methods, and inset maps of bioclimate subzones, floristic provinces, elevation, and plant biomass on the back side.
unfold_moreBrief presentations of the posters