| 1. |
- Elberling, Bo, et al.
(författare)
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Soil and Plant Community Characteristics and Dynamics at Zackenberg
- 2008
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Ingår i: High-arctic ecosystem dynamics in a changing climate - Ten years of monitoring and research at Zackenberg Research Station, Northeast Greenland (Advances in Ecological Research). - 0065-2504. - 9780123736659 ; 40, s. 223-248
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Arctic soils hold large amounts of nutrients in the weatherable minerals and the soil organic matter, which slowly decompose. The decomposition processes release nutrients to the plant-available nutrient pool as well as greenhouse gases to the atmosphere. Changes in climatic conditions, for example, changes in the distribution of snow, water balance and the length of the growing season, are likely to affect the complex interactions between plants, abiotic and biotic soil processes as well as the composition of soil micro- and macro-fauna and thereby the overall decomposition rates. These interactions, in turn, will influence soil-plant functioning and vegetation composition in the short as well as in the long term. In this chapter, we report on soils and. plant communities and their distribution patterns in the valley Zackenbergdalen and focus on the detailed investigations within five dominating plant communities. These five communities are located along an ecological gradient in the landscape and are closely related to differences in water availability. They are therefore indirectly formed as a result of the distribution of landforms, redistribution of snow and drainage conditions. Each of the plant communities is closely related to specific nutrient levels and degree of soil development including soil element accumulation and translocation, for example, organic carbon. Results presented here show that different parts of the landscape have responded quite differently to the same overall climate changes the last 10 years and thus, most likely in the future too. Fens represent the wettest sites holding large reactive buried carbon stocks. A warmer climate will cause a permafrost degradation, which most likely will result in anoxic decomposition and increasing methane emissions. However, the net gas emissions at fen sites are sensitive to long-term changes in the water table level. Indeed, increasing maximum active layer depth at fen sites has been recorded together with a decreasing water level at Zackenberg. This is in line with the first signs of increasing extension of grasslands at the expense of fens. In contrast, the most exposed and dry areas have less soil carbon, and decomposition processes are periodically water limited. Here, an increase in air temperatures may increase active layer depth more than at fen sites, but water availability will be critical in determining nutrient cycling and plant production. Field manipulation experiments of increasing temperature, water supply and nutrient addition show that soil-plant interactions are sensitive to these variables. However, additional plant-specific investigations are needed before net effects of climate changes on different landscape and plant communities can be integrated in a landscape context and used to assess the net ecosystem effect of future climate scenarios.
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| 2. |
- Andersson Djurfeldt, Agnes, et al.
(författare)
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Epilogue - Doing Longitudinal Research
- 2021
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Ingår i: Prosperity in Rural Africa? : Insights into Wealth, Assets, and Poverty from Longitudinal Studies in Tanzania - Insights into Wealth, Assets, and Poverty from Longitudinal Studies in Tanzania. - 9780198865872
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 3. |
- 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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| 4. |
- Sandström Malinowski, Ewa, 1945, et al.
(författare)
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Hot Lime Mortar in Conservation: Repair and Replastering of the Facades of Läckö Castle
- 2012
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Ingår i: Building Limes in Conservation. - Donhead St Mary, Shaftesbury, Storbritannien : Donhead Publishing Ltd. - 978 1 873394 95 3 ; , s. 271-294
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Bokkapitel (refereegranskat)abstract
- Kapitlet ingår i den tredje delen av antologin: "Building Limes in Conservation" vars rubrik är Rediscovering "Methods and techniques". Det reviderade kapitlet publicerades först som artikel i Journal of Architectural Conservation (mars 2011). Artikelns abstract: "The Slaking quick lime directly with sand produces ‘hot lime’ and ‘hot lime mortars’. The repair and conservation of the façades of Läckö Castle in western Sweden is a rare example of this method being used in conservation practice. The objective of the Läckö project has been to develop a repair mortar that is technically compatible with those used in the original structure. The hypothesis is that hot lime could provide the key to replicating the qualities of the original lime-rich, historic mortars and would thus be suitable for making compatible mortars. This paper is an account of the experience and describes the processes of burning lime and slaking and the production and application of ‘hot-lime’ mortar. It also considers the properties and advantages and disadvantages of hot lime mortar compared with those of traditionally ‘wet-slaked mortar’. The experience so far has been encouraging."
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