0000000000161820

AUTHOR

Pekka Niittynen

Bioclimatic atlas of the terrestrial Arctic

AbstractThe Arctic is the region on Earth that is warming at the fastest rate. In addition to rising means of temperature-related variables, Arctic ecosystems are affected by increasingly frequent extreme weather events causing disturbance to Arctic ecosystems. Here, we introduce a new dataset of bioclimatic indices relevant for investigating the changes of Arctic terrestrial ecosystems. The dataset, called ARCLIM, consists of several climate and event-type indices for the northern high-latitude land areas > 45°N. The indices are calculated from the hourly ERA5-Land reanalysis data for 1950–2021 in a spatial grid of 0.1 degree (~9 km) resolution. The indices are provided in three subsets…

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Plant trait‐environment relationships in tundra are consistent across spatial scales

Patterns and processes shaping ecosystems vary across spatiotemporal scales. As plant functional traits reflect ecosystem properties, investigating their relationships with environment provides an important tool to understand and predict ecosystem structure and functioning. This is particularly important in the tundra where a changing climate may trigger severe alterations in plant communities as both summer and winter conditions are changing. Here, we investigate the relationships between key environmental drivers including summer temperature, snow persistence, topographic position and soil pH, and species height, specific leaf area (SLA) and seed mass as plant traits. The study is carried…

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Distance decay 2.0. A global synthesis of taxonomic and functional turnover in ecological communities

Caio Graco-Roza was funded by the Coordination for the Improvement of Higher Education Personnel (CAPES), the Carlos Chagas Filho Research Support Foundation (FAPERJ) and the Ella and Georg Erhnrooth Foundation; Jan Altman by research grants INTER-EXCELLENCE LTAUSA19137 provided by Czech Ministry of Education, Youth and Sports, 20-05840Y of the Czech Science Foundation, and long-term research development project no. RVO 67985939 of the Czech Academy of Sciences; Otso Ovaskainen was funded by Academy of Finland (grant no. 309581), Jane and Aatos Erkko Foundation, Research Council of Norway through its Centres of Excellence Funding Scheme (223257), and the European Research Council (ERC) unde…

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Water as a multifaceted environmental filter of tundra vegetation

The hydrological cycle of tundra has intensified due to accelerated environmental changes. Climatic changes affect tundra vegetation by altering water conditions (1). Plant-available water mediates climate change impacts, namely against rising temperatures and changing snow dynamics (2). Vegetation is limited by water resources, but water forms also major stress and disturbance. However, climate change impact studies often cover water inadequately in cold regions, which are assumed to be energy-limited ecosystems (3). Thus, we used statistical modelling methods to test if the inclusion of different water factors improved species distribution, species richness, and community composition mode…

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The underestimated role of winter microclimate for Arctic tundra vegetation

Assessing the impacts of climate change on biodiversity and developing climate-wise conservation planning requires in-depth understanding of the key drivers of species distributions and assemblages. This is particularly important in Arctic environments which will face the most notable climatic changes worldwide. The search for main determinants of biodiversity patterns in high-latitude ecosystems has focused on growing season conditions, but there is increasing amount of evidence suggesting that wintertime conditions can be equally or even more important factors for Arctic biodiversity than summer conditions (1, 2). Yet, large uncertainties exist regarding the role of winter climate in cont…

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