| 1. |
- Arndt, D. S., et al.
(författare)
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STATE OF THE CLIMATE IN 2017
- 2018
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Ingår i: Bulletin of The American Meteorological Society - (BAMS). - : American Meteorological Society. - 0003-0007 .- 1520-0477. ; 99:8, s. S1-S310
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Forskningsöversikt (refereegranskat)
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| 2. |
- Barrio, I. C., et al.
(författare)
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Biotic interactions mediate patterns of herbivore diversity in the Arctic
- 2016
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Ingår i: Global Ecology and Biogeography. - : Wiley-Blackwell. - 1466-822X .- 1466-8238. ; 25:9, s. 1108-1118
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Tidskriftsartikel (refereegranskat)abstract
- Aim: Understanding the forces shaping biodiversity patterns, particularly for groups of organisms with key functional roles, will help predict the responses of ecosystems to environmental changes. Our aim was to evaluate the relative role of different drivers in shaping the diversity patterns of vertebrate herbivores, a group of organisms exerting a strong trophic influence in terrestrial Arctic ecosystems. This biome, traditionally perceived as homogeneous and low in biodiversity, includes wide variation in biotic and physical conditions and is currently undergoing major environmental change. Location: The Arctic (including the High Arctic, Low Arctic and Subarctic) MethodsWe compiled available data on vertebrate (birds and mammals) herbivore distribution at a pan-Arctic scale, and used eight variables that represent the most relevant hypotheses for explaining patterns of species richness. We used range maps rasterized on a 100kmx100km equal-area grid to analyse richness patterns of all vertebrate herbivore species combined, and birds and mammalian herbivores separately. Results: Overall, patterns of herbivore species richness in the Arctic were positively related to plant productivity (measured using the normalized difference vegetation index) and to the species richness of predators. Greater species richness of herbivores was also linked to areas with a higher mean annual temperature. Species richness of avian and mammalian herbivores were related to the distance from the coast, with the highest avian richness in coastal areas and mammalian richness peaking further inland. Main conclusions: Herbivore richness in the Arctic is most strongly linked to primary productivity and the species richness of predators. Our results suggest that biotic interactions, with either higher or lower trophic levels or both, can drive patterns of species richness at a biome-wide scale. Rapid ongoing environmental changes in the Arctic are likely to affect herbivore diversity through impacts on both primary productivity and changes in predator communities via range expansion of predators from lower latitudes.
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| 3. |
- Horstkotte, Tim, et al.
(författare)
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Human-animal agency in reindeer management : Sami herders' perspectives on vegetation dynamics under climate change
- 2017
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Ingår i: Ecosphere. - : WILEY. - 2150-8925 .- 2150-8925. ; 8:9
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Tidskriftsartikel (refereegranskat)abstract
- Many primary livelihoods in Arctic and sub-Arctic regions experience accelerating effects of environmental change. The often close connection between indigenous peoples and their respective territories allows them to make detailed observations of how these changes transform the landscapes where they practice their daily activities. Here, we report Sami reindeer herders' observations based on their long-term inhabitance and use of contrasting pastoral landscapes in northern Fennoscandia. In particular, we focus on the capacity for various herd management regimes to prevent a potential transformation of open tundra vegetation to shrubland or woodland. Sami herders did not confirm a substantial, rapid, or large-scale transformation of treeless tundra areas into shrub-and/or woodlands. However, where they observe encroachment of open tundra landscapes, a range of factors was deemed responsible. These included abiotic conditions, anthropogenic influences, and the direct and indirect effects of reindeer. The advance of the mountain birch tree line was in some cases associated with reduced or discontinued grazing and firewood cutting, depending on the seasonal significance of these particular areas. Where the tree line has risen in elevation and/or latitude, herding practices have by necessity adapted to these changes. Exploiting the capacity of reindeer impacts on vegetation as a conservation tool offers time-tested adaptive strategies of ecosystem management to counteract a potential encroachment of the tundra by woody plants. However, novel solutions in environmental governance involve difficult trade-offs for ecologically sustainable, economically viable, and socially desirable management strategies.
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| 4. |
- Horstkotte, Tim, et al.
(författare)
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Quantifying the Implications of Different Land Users' Priorities in the Management of Boreal Multiple-Use Forests
- 2016
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Ingår i: Environmental Management. - : Springer Science and Business Media LLC. - 0364-152X .- 1432-1009. ; 57:4, s. 770-783
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Tidskriftsartikel (refereegranskat)abstract
- In the management of natural resources, conflicting interests and objectives among different stakeholders often need to be considered. Here, we examine how two contrasting management scenarios of boreal forests in northern Sweden differ in their consequences on forest structural composition and the economic gains at harvest. Management strategies prioritize either (i) forest characteristics that promote grazing resources for reindeer herded by the indigenous Sami, or (ii) timber production as practiced in Sweden today. When prioritizing reindeer grazing, forest stands develop a higher abundance of older age classes with larger trees and lower stem density, which reduces harvest and revenue levels by approximately 20 % over a 100-year period. The differences between these strategies illustrate the complexity in finding a trade-off for coexistence between industrial land users and other livelihoods that share the same landscape. Political support and institutional solutions are necessary to initiate changes in policy in finding such trade-offs in the management of environmental resources and thereby influence the optimal distribution of costs and benefits between different actors.
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| 5. |
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| 6. |
- Horstkotte, Tim, 1981-, et al.
(författare)
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Successional pathways of terrestrial lichens in changing Swedish boreal forests
- 2019
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Ingår i: Forest Ecology and Management. - : Elsevier. - 0378-1127 .- 1872-7042. ; 453
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Tidskriftsartikel (refereegranskat)abstract
- The current decline of terrestrial lichens in Swedish boreal forests is a major challenge for reindeer husbandry, as lichens constitute essential grazing resources for reindeer during winter. Using a 30-year data set covering northern Sweden, we explore how the successional dynamics of lichen cover depend on several forest characteristics, as well as management strategies regarding both reindeer and forestry. We found a 36% reduction of plots with lichen cover, with a decrease in lichen cover becoming more likely in recent years. Year-round presence of reindeer in forests, compared to winter grazing only, had slightly negative impacts on lichens. We found increases in lichen cover in young forests following final harvest. However, increasing basal areas as forest grow older affected lichens negatively and supported dominance of mosses. Forest management that prioritizes less dense forests with larger trees would therefore improve the ability of lichens to persist as forage resource for reindeer.
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| 7. |
- Keskitalo, E. Carina H., 1974-, et al.
(författare)
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"Generality of mis-fit"? : The real-life difficulty of matching scales in an interconnected world
- 2016
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Ingår i: Ambio. - : Springer. - 0044-7447 .- 1654-7209. ; 45:6, s. 742-752
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Tidskriftsartikel (refereegranskat)abstract
- A clear understanding of processes at multiple scales and levels is of special significance when conceiving strategies for human-environment interactions. However, understanding and application of the scale concept often differ between administrative-political and ecological disciplines. These mirror major differences in potential solutions whether and how scales can, at all, be made congruent. As a result, opportunities of seeking "goodness-of-fit" between different concepts of governance should perhaps be reconsidered in the light of a potential "generality of mis-fit." This article reviews the interdisciplinary considerations inherent in the concept of scale in its ecological, as well as administrative-political, significance and argues that issues of how to manage "mis-fit" should be awarded more emphasis in social-ecological research and management practices. These considerations are exemplified by the case of reindeer husbandry in Fennoscandia. Whilst an indigenous small-scale practice, reindeer husbandry involves multi-level ecological and administrative-political complexities-complexities that we argue may arise in any multi-level system.
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| 8. |
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Reindeer husbandry under global change in the tundra region of Northern Fennoscandia
- 2017
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Samlingsverk (redaktörskap) (övrigt vetenskapligt/konstnärligt)abstract
- The Nordic Centre of Excellence (NCoE) TUNDRA ("How to preserve the tundra in a changing climate") has been a 5-year project (2011–15) within the Top-Level Research Initiative (TRI) by NordForsk. This report combines the key results and a synthesis of the NCoE TUNDRA with earlier research to provide a comprehen- sive picture of the interplay between the tundra ecosystem, climate change and reindeer husbandry to relevant stakeholders. Most recent climate projections suggest that by the 2070s, temperature conditions that are warm enough for tree growth (> 10 °C average temperature during summer months) will cover almost all of northern Fennoscandia, excluding only the highest-altitude areas of the Scandinavian mountains. A warming climate will promote growth of shrubs and trees, a process that decreases the area of the tundra biome remarkably. The projected increase in spring temperatures will enhance snow melting. Together with the expansion and densification of shrub vegetation, this can significantly decrease surface reflectance (al- bedo), and have an amplifying feedback on global climate warming. Therefore, hindering shrub expansion and preserving the circumpolar high albedo tundra biome would serve as climate change mitigation. Herbivores (animals feeding on plants) have a strong impact on vegetation communities. The most important herbivores in Northern Fennoscandia include large mammals (reindeer), small mammals (rodents), and insects (geometrid moths). Their exact effect, however, varies between the animal groups and their population dynamics, seasons, weather conditions, and vegetation communities, and is dependent also on the combined impact of these animal groups. Reindeer grazing in particular has the potential to counter-impact the climate-induced shrubification. The maximum grazing impact on woody plants is obtained if reindeer are present in a region during early growing season in June and early July. In addition, grazing has an impact on plant biodiversity. By preventing the invasion of trees, tall shrubs and forbs, reindeer maintain the openness of the tundra, which is a precondition for the survival of many small-sized arctic plant species. Although grazing may disturb also these plant species, the net impact of intense summer grazing can be positive at the population level. From a transdisciplinary perspective, tundra is not only a biome, but also a social-ecological system (SES) incorporating humans and their activities, including reindeer husbandry. Decision-making involves various aspects of this complex social-ecological system and is, therefore, always a compromise and a matter of values and opinions. Reindeer husbandry exhibits major legal and administrative differences in local, regional, and state governance between Finland, Norway and Sweden. Anticipated changes in climate and within the societies require reindeer husbandry to adapt to these transformations. Future is notpre-determined but unveils itself as a chain of decisions and actions. Therefore, various scenarios of the future of the social-ecological system in Northern Fennoscandia – including reindeer husbandry – can be foresighted depending on the circumstances, decisions and actions. Current tensions between stakeholders – including reindeer herders, other land users, Sámi and non-Sámi individuals, and the governance system – stem from different values regarding ecological, cultural, social, and economic matters. These tensions may inhibit fruitful discussion and feasible decisions, and may lead to a future that is undesirable for many, if not all parties. At present, there is too little interaction, and inadequate, unequal discussion between the stakeholders. From the herders' perspective, unclear legislation and lack of self-determination are considered as threats for the livelihood. To improve the quality of decision making, planning and actions regarding future land use and livelihoods should be co-designed by different stakeholders. To overcome the historical apprehension between the parties, a neutral boundary organisation might serve as an appreciated mediator.
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| 9. |
- Uboni, Alessia, et al.
(författare)
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Long-Term Trends and Role of Climate in the Population Dynamics of Eurasian Reindeer
- 2016
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 11:6
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Tidskriftsartikel (refereegranskat)abstract
- Temperature is increasing in Arctic and sub-Arctic regions at a higher rate than anywhere else in the world. The frequency and nature of precipitation events are also predicted to change in the future. These changes in climate are expected, together with increasing human pressures, to have significant impacts on Arctic and sub-Arctic species and ecosystems. Due to the key role that reindeer play in those ecosystems, it is essential to understand how climate will affect the region's most important species. Our study assesses the role of climate on the dynamics of fourteen Eurasian reindeer (Rangifer tarandus) populations, using for the first time data on reindeer abundance collected over a 70-year period, including both wild and semi-domesticated reindeer, and covering more than half of the species' total range. We analyzed trends in population dynamics, investigated synchrony among population growth rates, and assessed the effects of climate on population growth rates. Trends in the population dynamics were remarkably heterogeneous. Synchrony was apparent only among some populations and was not correlated with distance among population ranges. Proxies of climate variability mostly failed to explain population growth rates and synchrony. For both wild and semi-domesticated populations, local weather, biotic pressures, loss of habitat and human disturbances appear to have been more important drivers of reindeer population dynamics than climate. In semi-domesticated populations, management strategies may have masked the effects of climate. Conservation efforts should aim to mitigate human disturbances, which could exacerbate the potentially negative effects of climate change on reindeer populations in the future. Special protection and support should be granted to those semi-domesticated populations that suffered the most because of the collapse of the Soviet Union, in order to protect the livelihood of indigenous peoples that depend on the species, and the multi-faceted role that reindeer exert in Arctic ecosystems.
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