| 1. |
- Björkman, Anne, 1981, et al.
(författare)
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Plant functional trait change across a warming tundra biome
- 2018
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 562:7725, s. 57-62
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Tidskriftsartikel (refereegranskat)abstract
- The tundra is warming more rapidly than any other biome on Earth, and the potential ramifications are far-reaching because of global feedback effects between vegetation and climate. A better understanding of how environmental factors shape plant structure and function is crucial for predicting the consequences of environmental change for ecosystem functioning. Here we explore the biome-wide relationships between temperature, moisture and seven key plant functional traits both across space and over three decades of warming at 117 tundra locations. Spatial temperature–trait relationships were generally strong but soil moisture had a marked influence on the strength and direction of these relationships, highlighting the potentially important influence of changes in water availability on future trait shifts in tundra plant communities. Community height increased with warming across all sites over the past three decades, but other traits lagged far behind predicted rates of change. Our findings highlight the challenge of using space-for-time substitution to predict the functional consequences of future warming and suggest that functions that are tied closely to plant height will experience the most rapid change. They also reveal the strength with which environmental factors shape biotic communities at the coldest extremes of the planet and will help to improve projections of functional changes in tundra ecosystems with climate warming.
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| 2. |
- Björkman, Anne, 1981, et al.
(författare)
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Tundra Trait Team: A database of plant traits spanning the tundra biome
- 2018
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Ingår i: Global Ecology and Biogeography. - : Wiley. - 1466-822X .- 1466-8238. ; 27:12, s. 1402-1411
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Tidskriftsartikel (refereegranskat)abstract
- © 2018 The Authors Global Ecology and Biogeography Published by John Wiley & Sons Ltd Motivation: The Tundra Trait Team (TTT) database includes field-based measurements of key traits related to plant form and function at multiple sites across the tundra biome. This dataset can be used to address theoretical questions about plant strategy and trade-offs, trait–environment relationships and environmental filtering, and trait variation across spatial scales, to validate satellite data, and to inform Earth system model parameters. Main types of variable contained: The database contains 91,970 measurements of 18 plant traits. The most frequently measured traits (> 1,000 observations each) include plant height, leaf area, specific leaf area, leaf fresh and dry mass, leaf dry matter content, leaf nitrogen, carbon and phosphorus content, leaf C:N and N:P, seed mass, and stem specific density. Spatial location and grain: Measurements were collected in tundra habitats in both the Northern and Southern Hemispheres, including Arctic sites in Alaska, Canada, Greenland, Fennoscandia and Siberia, alpine sites in the European Alps, Colorado Rockies, Caucasus, Ural Mountains, Pyrenees, Australian Alps, and Central Otago Mountains (New Zealand), and sub-Antarctic Marion Island. More than 99% of observations are georeferenced. Time period and grain: All data were collected between 1964 and 2018. A small number of sites have repeated trait measurements at two or more time periods. Major taxa and level of measurement: Trait measurements were made on 978 terrestrial vascular plant species growing in tundra habitats. Most observations are on individuals (86%), while the remainder represent plot or site means or maximums per species. Software format: csv file and GitHub repository with data cleaning scripts in R; contribution to TRY plant trait database (www.try-db.org) to be included in the next version release.
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| 3. |
- Ayllón, Daniel, et al.
(författare)
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Keeping modelling notebooks with TRACE : Good for you and good for environmental research and management support
- 2021
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Ingår i: Environmental Modelling & Software. - : Elsevier BV. - 1364-8152 .- 1873-6726. ; 136
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Tidskriftsartikel (refereegranskat)abstract
- The acceptance and usefulness of simulation models are often limited by the efficiency, transparency, reproducibility, and reliability of the modelling process. We address these issues by suggesting that modellers (1) “trace” the iterative modelling process by keeping a modelling notebook corresponding to the laboratory notebooks used by empirical researchers, (2) use a standardized notebook structure and terminology based on the existing TRACE documentation framework, and (3) use their notebooks to compile TRACE documents that supplement publications and reports. These practices have benefits for model developers, users, and stakeholders: improved and efficient model design, analysis, testing, and application; increased model acceptance and reuse; and replicability and reproducibility of the model and the simulation experiments. Using TRACE terminology and structure in modelling notebooks facilitates production of TRACE documents. We explain the rationale of TRACE, provide example TRACE documents, and suggest strategies for keeping “TRACE Modelling Notebooks.”
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| 4. |
- Forchhammer, Mads C., et al.
(författare)
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Zackenberg in a circumpolar context
- 2008
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Ingår i: Advances in Ecological Research. - 0065-2504. ; 40, s. 499-544
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Throughout the Northern Hemisphere, changes in local and regional climate conditions are coupled to the recurring and persistent large-scale patterns of pressure and circulation anomalies spanning vast geographical areas, the so-called teleconnection patterns. Indeed, the atmospheric fluctuations described by the North Atlantic Oscillation (NAO) are closely associated with the last four decades of inter-annual variability in local snow and ice conditions observed in the Arctic. Since the NAO has also been connected with changes in the global climate, the behaviour of species, communities and other ecosystem elements at Zackenberg in relation to the NAO enables us to view these in circumpolar and global contexts. Large-scale systems like the NAO constitute the link between the global change and local climate variability to which ecosystem components respond. Here, we place selected ecosystem elements from the monitoring programme Zackenberg Basic presented in previous chapters in a circumpolar context related to NAO-mediated climatic changes. We begin by linking the local variability in winter weather conditions at Zackenberg to fluctuations in the NAO. We then proceed by linking the observed intra- and inter-annual behaviour of selected ecosystem elements to changes in the NAO. The functional ecosystem characteristics in focus are landscape gas exchange dynamics phenological patterns at different trophic levels, consumer-resource dynamics and community stability. The influence of the NAO is presented and discussed in a broader perspective based on information obtained from other arctic localities. The relation between the NAO and the Zackenberg winter weather, is nonlinear, reflecting differential effects of the NAO as the index moves between high and low phases. The inverse hyperbolic relationship found between the NAO and the amount of winter snow was also evident as non-linear response in organisms and systems to inter-annual changes in the NAO. Responses investigated included growth and reproduction in plants and animals, population dynamics and synchrony, inter-trophic interactions and community stability together with system feedback dynamics.
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| 5. |
- van Beest, Floris M, et al.
(författare)
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Classifying grey seal behaviour in relation to environmental variability and commercial fishing activity -a multivariate hidden Markov model
- 2019
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 9:1
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Tidskriftsartikel (refereegranskat)abstract
- Classifying movement behaviour of marine predators in relation to anthropogenic activity and environmental conditions is important to guide marine conservation. We studied the relationship between grey seal (Halichoerus grypus) behaviour and environmental variability in the southwestern Baltic Sea where seal-fishery conflicts are increasing. We used multiple environmental covariates and proximity to active fishing nets within a multivariate hidden Markov model (HMM) to quantify changes in movement behaviour of grey seals while at sea. Dive depth, dive duration, surface duration, horizontal displacement, and turning angle were used to identify travelling, resting and foraging states. The likelihood of seals foraging increased in deeper, colder, more saline waters, which are sites with increased primary productivity and possibly prey densities. Proximity to active fishing net also had a pronounced effect on state occupancy. The probability of seals foraging was highest <5 km from active fishing nets (51%) and decreased as distance to nets increased. However, seals used sites <5 km from active fishing nets only 3% of their time at sea highlighting an important temporal dimension in seal-fishery interactions. By coupling high-resolution oceanographic, fisheries, and grey seal movement data, our study provides a scientific basis for designing management strategies that satisfy ecological and socioeconomic demands on marine ecosystems.
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| 6. |
- von Oppen, Jonathan, et al.
(författare)
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Cross-scale regulation of seasonal microclimate by vegetation and snow in the Arctic tundra
- 2022
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Ingår i: Global Change Biology. - : Wiley. - 1354-1013 .- 1365-2486. ; 28:24, s. 7296-7312
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Tidskriftsartikel (refereegranskat)abstract
- Climate warming is inducing widespread vegetation changes in Arctic tundra ecosystems, with the potential to alter carbon and nutrient dynamics between vegetation and soils. Yet, we lack a detailed understanding of how variation in vegetation and topography influences fine-scale temperatures (“microclimate”) that mediate these dynamics, and at what resolution vegetation needs to be sampled to capture these effects. We monitored microclimate at 90 plots across a tundra landscape in western Greenland. Our stratified random study design covered gradients of topography and vegetation, while nested plots (0.8–100 m2) enabled comparison across different sampling resolutions. We used Bayesian mixed-effect models to quantify the direct influence of plot-level topography, moisture and vegetation on soil, near-surface and canopy-level temperatures (−6, 2, and 15 cm). During the growing season, colder soils were predicted by shrub cover (−0.24°C per 10% increase), bryophyte cover (−0.35°C per 10% increase), and vegetation height (−0.17°C per 1 cm increase). The same three factors also predicted the magnitude of differences between soil and above-ground temperatures, indicating warmer soils at low cover/height, but colder soils under closed/taller canopies. These findings were consistent across plot sizes, suggesting that spatial predictions of microclimate may be possible at the operational scales of satellite products. During winter, snow cover (+0.75°C per 10 snow-covered days) was the key predictor of soil microclimate. Topography and moisture explained little variation in the measured temperatures. Our results not only underline the close connection of vegetation and snow with microclimate in the Arctic tundra but also point to the need for more studies disentangling their complex interplay across tundra environments and seasons. Future shifts in vegetation cover and height will likely mediate the impact of atmospheric warming on the tundra soil environment, with potential implications for below-ground organisms and ecosystem functioning.
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