| 1. |
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| 2. |
- Bernes, Claes, et al.
(författare)
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What are the impacts of reindeer/caribou (Rangifer tarandus L.) on arctic and alpine vegetation? : A systematic review protocol
- 2013
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Ingår i: Environmental Evidence. - : BioMed Central (BMC). - 2047-2382. ; 2
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Tidskriftsartikel (refereegranskat)abstract
- Background: Reindeer and caribou (both belonging to the species Rangifer tarandus L.) are among the most important large herbivores in Eurasia’s and North America’s arctic, alpine and boreal zones. In Sweden, the impact of reindeer grazing on arctic and alpine vegetation has recently been re-evaluated. In the 1990s, records of grazing-related vegetation degradation helped to form a widespread perception that some mountain areas were overgrazed. However, later analyses have shown no evidence of large-scale overutilisation of reindeer ranges in the Swedish mountains.The present-day consensus is that overgrazing has been temporary and local, and that it rarely has caused permanent damage, but it is imperative to examine the scientific support for these views. Moreover, the Swedish Parliament has adopted an environmental quality objective according to which it is essential to preserve ‘a mountain landscape characterised by grazing’. No details have been given on how this goal is to be interpreted, which is another reason why the significance of reindeer grazing for arctic/alpine vegetation needs to be assessed.This protocol presents the methodology that will be used in a systematic review of the impact of reindeer herbivory in arctic and alpine ecosystems. The focus will be on Fennoscandia, but data from other parts of the range of R. tarandus will be used when deemed appropriate.Methods: The review will be based on primary field studies that compare vegetation subject to different degrees of reindeer/caribou herbivory (including grazing and browsing as well as trampling). Such comparisons can be either temporal, spatial or both. The review will cover impacts of herbivory in arctic, subarctic, alpine and subalpine areas (including the forest-tundra ecotone) across the range of R. tarandus, but not in boreal forests. Relevant aspects of vegetation include cover (abundance), biomass, diversity (e.g. species richness), structure, composition (including functional groups) and productivity.
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| 3. |
- Cairns, David M., et al.
(författare)
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Comparing two methods for ageing trees with suppressed, diffuse-porous rings (Betula pubescens ssp. czerepanovii)
- 2012
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Ingår i: Dendrochronologia. - : Elsevier BV. - 1125-7865 .- 1612-0051. ; 30:4, s. 252-256
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Tidskriftsartikel (refereegranskat)abstract
- The annual growth rings of diffuse porous species such as mountain birch are often difficult to distinguish when samples are collected from trees that grow at treeline or in other harsh environments. In this study we document the differences in seedling and sapling ring counts obtained from two methods of analysis: a traditional analysis based on reflected light and low-power microscopy and one based on transmitted light with higher power magnification that uses thin-sections of the samples. Rings are easier to resolve using the more labor-intensive transmitted light method. Small rings are often missed when using the reflected light method, resulting in an underestimation of tree age. The dates estimated by the standard method agreed with those determined using the thin-sectioning method in 9.6% of the cases. Most commonly, the standard method gave a younger age than did thin-sectioning (72.4% of the trees). In only 18.03% of the cases did the standard method result in a greater age than did thin-sectioning. The reflected light method produced age estimations that were on average 1.37 years younger than those determined using the transmitted light method. The difference between the two methods was positively correlated with age and negatively correlated with mean ring-width. Age-class histograms based on the two methods show little difference at coarser aggregation levels (decades and pentads), but annualized age-class histograms have less agreement between the two methods. Therefore, we suggest using the more labor-intensive thin-sectioning method when annualized age counts are necessary in suppressed seedlings and saplings, for example, comparing tree establishment with annual climate conditions at treeline.
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| 4. |
- Gamfeldt, Lars, 1975, et al.
(författare)
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Higher levels of multiple ecosystem services are found in forests with more tree species
- 2013
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 4
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Tidskriftsartikel (refereegranskat)abstract
- Forests are of major importance to human society, contributing several crucial ecosystem services. Biodiversity is suggested to positively influence multiple services but evidence from natural systems at scales relevant to management is scarce. Here, across a scale of 400,000 km2, we report that tree species richness in production forests shows positive to positively hump-shaped relationships with multiple ecosystem services. These include production of tree biomass, soil carbon storage, berry production and game production potential. For example, biomass production was approximately 50% greater with five than with one tree species. In addition, we show positive relationships between tree species richness and proxies for other biodiversity components. Importantly, no single tree species was able to promote all services, and some services were negatively correlated to each other. Management of production forests will therefore benefit from considering multiple tree species to sustain the full range of benefits that the society obtains from forests.
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| 5. |
- Gilichinsky, Michael, et al.
(författare)
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Application of national forest inventory for remote sensing classification of ground lichen in nothern Sweden
- 2010
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Ingår i: ISPRS Archives. - : International Society for Photogrammetry and Remote Sensing. ; 38-4-8, s. 146-152
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Konferensbidrag (refereegranskat)abstract
- Lichen is a major forage resource for reindeer and may constitute up to 80% of a reindeer's winter diet. The reindeer grazing area in Sweden covers almost half of the country, with reindeer using mountainous areas in the summer and forested areas in the winter. Knowledge about the spatial distribution of ground lichens is important for both practical and sustainable decisionmaking purposes. Since the early 1980s, remote sensing research of lichen cover in northern environments has focused on reindeer grazing issues. The objective of the present study was to use lichen information from the Swedish Forest Inventory (NFI) for classification of satellite data into ground lichen classes. The classification procedure was focused on using of NFI plots as training sets for supervised classification of the ground lichen cover in purpose to classify areas with different lichen coverage. The present research has shown the advantage of use forest inventory plot data by assessment of three methods: mahalanobis distance (MD) classification, maximum likelihood (ML) classification and spectral mixture analysis (SMA). The results of this study demonstrate high classification accuracy of SPOT imagery in distinction between lichenabundant and lichen-poor areas by mahalanobis distance classifier (overall accuracy 84.3%, kappa=0.68). The highest classification accuracy for Landsat scene was achieved by maximumlikelihood classification (overall accuracy 76.8%, kappa=0.53). The continuation research on more detailed fragmentation of lichen cover into fractions is proposed.
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| 6. |
- Gilichinsky, Michael, et al.
(författare)
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Mapping ground lichens using forest inventory and optical satellite data
- 2011
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Ingår i: International Journal of Remote Sensing. - : Informa UK Limited. - 0143-1161 .- 1366-5901. ; 32:2, s. 455-472
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Tidskriftsartikel (refereegranskat)abstract
- Lichen is a major forage resource for reindeer and may constitute up to 80% of areindeer’s winter diet. The reindeer grazing area in Sweden covers almost half of thecountry, with reindeer using mountainous areas in the summer and forested areas inthe winter. Knowledge about the spatial distribution of ground lichens is importantfor both practical and decision-making purposes. Since the early 1980s, remotesensing research of lichen cover in northern environments has focused on reindeergrazing issues. The objective of this study was to use lichen information collected inthe Swedish National Forest Inventory (NFI) as training data to classify opticalsatellite images into ground lichen cover classes. The study site was located within thereindeer husbandry area in northern Sweden and consisted of the common areabetween two contiguous Satellite Pour l’Observation de la Terre (SPOT)-5 scenesand one Landsat-7 Enhanced Thematic Mapper Plus (ETMþ) scene. Three classificationmethods were tested: Mahalanobis distance, maximum likelihood andspectral mixture analysis. Post-classification calibration was applied using a membershipprobability threshold in order to match the NFI-measured proportions oflichen coverage classes. The classification results were assessed using an independentlycollected field dataset (229 validation areas). The results demonstrated highclassification accuracy of SPOT imagery for the classification of lichen-abundantand lichen-poor areas when using theMahalanobis distance classifier (overall accuracy84.3%, kappa ¼ 0.68). The highest classification accuracy for Landsat wasachieved using a maximum likelihood classification (overall accuracy 76.8%, kappa¼ 0.53). These results provided an initial indication of the utility of NFI data astraining data in the process of mapping lichen classes over large areas.
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| 7. |
- Horstkotte, Tim, 1981-
(författare)
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Contested Landscapes : social-ecological interactions between forestry and reindeer husbandry
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Throughout northern Fennoscandia, reindeer husbandry is a central part in the cultural heritage of the Sámi people. In its history, Sámi culture and reindeer husbandry have undergone significant adaptations to environmental, social and political challenges. Landscape changes on the winter grazing grounds were mainly driven by resource exploitation, especially by industrialized forestry. Important grazing resources were lost, i.e. terrestrial and arboreal lichens that constitute essential key elements in the herding year.In my thesis, I explore the consequences of these transformations in Swedish boreal forests for reindeer husbandry. The multi-disciplinary approach integrates interview studies, ecological fieldwork and theoretical modeling of forest development.I emphasize the understanding of landscapes as multi-dimensional concepts with ecological, social and economic components. They interact in determining the amount of landscape fragmentation in physical or administrative ways, or in enabling reindeer herders to move between different landscape elements. These elements, e.g. forest stands of different ages, can react differently to winter weather. Thus, they enable reindeer herders to adjust their grazing grounds according to the availability of forage, mediated by snow conditions. However, forestry practices have reduced the abundance of old-growth forests, and therewith the functionality of the landscape. By comparing snow conditions in different forest types, I show that multi-layered canopies can offer a more diverse pattern of snow hardness. However, the interaction between forest characteristics with snow is strongly dependent on weather conditions, e.g. the timing and intensity of warm spells. The prevalence of single-layered forest stands therefore can lead to a reduction in snow variability and potentially restricts the availability of suitable grazing grounds for reindeer. If snow conditions hinder reindeer in foraging on terrestrial lichens, old forests formerly supplied reindeer with arboreal lichens. I show how industrial forestry has reduced the availability of this emergency forage by the reduction of old forests and increased landscape fragmentation and analyze the consequences of different management strategies on future habitat availability for arboreal lichens. By integrating these results into a model of forest management, I offer insights into consequences arising from different priorities that either favor timber production or the development of lichen-rich grazing grounds.In conclusion, I emphasize the importance of landscape diversity, as well as the ability to make use of this diversity, as a source of adaptability of reindeer husbandry to changes in grazing conditions by e.g. winter weather dynamics. A shared future of reindeer husbandry and forestry could be fostered by encouraging the social-ecological co-evolution of multiple use landscapes and the enhancement of the cultural and biological significance of the Swedish boreal forests.
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| 8. |
- Horstkotte, Tim, 1981-, et al.
(författare)
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Exploring the multiple use of boreal landscapes : the importance of social-ecological diversity for mobility and flexibility
- 2014
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Ingår i: Human Ecology. - : Springer Science and Business Media LLC. - 0300-7839 .- 1572-9915. ; 42:5, s. 671-682
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Tidskriftsartikel (refereegranskat)abstract
- Sustainable multiple use of landscapes can be a challenging task for the stakeholders involved, especially when they have competing interests with respect to natural resource management. In this paper we analyze the consequences associated with “landscape diversity”, including the interactions between environmental, administrative and societal factors. As a case study, we describe winter land use for reindeer husbandry in the boreal forest in Northern Sweden, a resource that is also used for commercial timber production. We show how and why the interactions between the three factors associated with landscape diversity affect reindeer herding and the options for responding to change. Multi-dimensional landscape diversity can either (i) promote flexibility in the face of change in the form of mobility or (ii) create fragmentation that restricts adaption to changes. This is a result of the dynamic patterns of diverse landscape structures, created by administrative and societal choices. Because such landscape patterns react differently to environmental variability within a season and between years, landscape functions adjusted to the dynamics of environmental variables could help to provide continuity of grazing resources in both space and time and ensure that reindeer husbandry remains resilient to changes. Because of the unequal distribution of power and capacity for decision making, social learning between the two stakeholders can help to balance trade-offs between both types of land user, allowing them to coexist in a landscape shaped by diverse values, priorities and management practices.
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| 9. |
- Horstkotte, Tim, et al.
(författare)
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The legacy of logging-estimating arboreal lichen occurrence in a boreal multiple-use landscape on a two century scale
- 2011
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Ingår i: PLOS ONE. - : Public library of science. - 1932-6203. ; 6:12, s. e28779-
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Tidskriftsartikel (refereegranskat)abstract
- In northern Sweden, the availability of arboreal lichens (Bryoria fuscescens, Alectoria sarmentosa) as winter grazing resources is an important element in reindeer husbandry. With the industrialization of forestry, forests rich in arboreal lichens have diminished considerably. Here, we analyze how forestry has impacted lichen availability from the 1920's to the present day and model its future development assuming different forest management scenarios. We recorded the current occurrence of B. fuscescens in 144 sampling plots, stratified by forest age class and dominant tree species in a 26,600 ha boreal forest landscape that is used for both reindeer herding and forestry. Lichen abundance was visually estimated in four classes: none, sparse, moderate and abundant. A binary logistic model using forest age as the independent variable was developed to predict the probability of lichens being present. Using this model, we found that lichens were present in stands that are at least 63 years old. Because of the relative paucity of stands rich in arboreal lichens, it was not possible to reliably determine how age affects the variation in abundance of older forest stands. The historical development of forests where arboreal lichens could potentially occur was studied using historic forestry records dating back 80 years. Between 1926 and the present day, forestry has reduced the cover of forests older than 60 years from 84% to 34%. The likely future spatial coverage of these stands over the next 120 years was estimated for two different management scenarios and an unmanaged reference scenario, using the Heureka strategic planning program. Under both the "business as usual'' scenario and that involving more intensive forestry, continued decreases in lichen availability are projected. Our results emphasize the importance of alternative forestry practices, such as prolonged rotation periods, to increase the availability of arboreal lichens as a grazing resource for reindeer.
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| 10. |
- Johansson Jänkänpää, Hanna, et al.
(författare)
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Non-photochemical quenching capacity in arabidopsis thaliana affects herbivore behaviour
- 2013
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 8:1, s. e53232-
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Tidskriftsartikel (refereegranskat)abstract
- Under natural conditions, plants have to cope with numerous stresses, including light-stress and herbivory. This raises intriguing questions regarding possible trade-offs between stress defences and growth. As part of a program designed to address these questions we have compared herbivory defences and damage in wild type Arabidopsis thaliana and two "photoprotection genotypes", npq4 and oePsbS, which respectively lack and overexpress PsbS (a protein that plays a key role in qE-type non-photochemical quenching). In dual-choice feeding experiments both a specialist (Plutella xylostella) and a generalist (Spodoptera littoralis) insect herbivore preferred plants that expressed PsbS most strongly. In contrast, although both herbivores survived equally well on each of the genotypes, for oviposition female P. xylostella adults preferred plants that expressed PsbS least strongly. However, there were no significant differences between the genotypes in levels of the 10 most prominent glucosinolates; key substances in the Arabidopsis anti-herbivore chemical defence arsenal. After transfer from a growth chamber to the field we detected significant differences in the genotypes' metabolomic profiles at all tested time points, using GC-MS, but no consistent "metabolic signature'' for the lack of PsbS. These findings suggest that the observed differences in herbivore preferences were due to differences in the primary metabolism of the plants rather than their contents of typical "defence compounds". A potentially significant factor is that superoxide accumulated most rapidly and to the highest levels under high light conditions in npq4 mutants. This could trigger changes in planta that are sensed by herbivores either directly or indirectly, following its dismutation to H2O2.
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