| 1. |
- Granath, Gustaf, et al.
(author)
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Environmental and taxonomic controls of carbon and oxygen stable isotope composition in Sphagnum across broad climatic and geographic ranges
- 2018
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In: Biogeosciences. - : Copernicus Publications. - 1726-4170 .- 1726-4189. ; 15:16, s. 5189-5202
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Journal article (peer-reviewed)abstract
- Rain-fed peatlands are dominated by peat mosses (Sphagnum sp.), which for their growth depend on nutrients, water and CO2 uptake from the atmosphere. As the isotopic composition of carbon (C-12(,)13) and oxygen (O-16(,)18) of these Sphagnum mosses are affected by environmental conditions, Sphagnum tissue accumulated in peat constitutes a potential long-term archive that can be used for climate reconstruction. However, there is inadequate understanding of how isotope values are influenced by environmental conditions, which restricts their current use as environmental and palaeoenvironmental indicators. Here we tested (i) to what extent C and O isotopic variation in living tissue of Sphagnum is speciesspecific and associated with local hydrological gradients, climatic gradients (evapotranspiration, temperature, precipitation) and elevation; (ii) whether the C isotopic signature can be a proxy for net primary productivity (NPP) of Sphagnum; and (iii) to what extent Sphagnum tissue delta O-18 tracks the delta O-18 isotope signature of precipitation. In total, we analysed 337 samples from 93 sites across North America and Eurasia us ing two important peat-forming Sphagnum species (S. magellanicum, S. fuscum) common to the Holarctic realm. There were differences in delta C-13 values between species. For S. magellanicum delta C-13 decreased with increasing height above the water table (HWT, R-2 = 17 %) and was positively correlated to productivity (R-2 = 7 %). Together these two variables explained 46 % of the between-site variation in delta C-13 values. For S. fuscum, productivity was the only significant predictor of delta C-13 but had low explanatory power (total R-2 = 6 %). For delta O-18 values, approximately 90 % of the variation was found between sites. Globally modelled annual delta O-18 values in precipitation explained 69 % of the between-site variation in tissue delta O-18. S. magellanicum showed lower delta O-18 enrichment than S. fuscum (-0.83 %0 lower). Elevation and climatic variables were weak predictors of tissue delta O-18 values after controlling for delta O-18 values of the precipitation. To summarize, our study provides evidence for (a) good predictability of tissue delta O-18 values from modelled annual delta O-18 values in precipitation, and (b) the possibility of relating tissue delta C-13 values to HWT and NPP, but this appears to be species-dependent. These results suggest that isotope composition can be used on a large scale for climatic reconstructions but that such models should be species-specific.
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| 2. |
- Waddington, David, et al.
(author)
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Cargovibes: Human response to vibration due to freight rail trafiic
- 2015
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In: Proceedings of 22nd International Congress on Sound and Vibration, 12 - 16 July, Florence, Italy 2015. - : Informa UK Limited. ; 3:4, s. 233-48
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Conference paper (other academic/artistic)abstract
- The aim of this paper is to present an overview of the research concerning human response to vibration conducted in the EU FP7 CargoVibes project. The European Union funded pro-ject CargoVibes involved ten partners from eight nations and ran from April 2011 to April 2014. The project was concerned with railway-induced ground-borne vibration affecting res-idents close to freight lines, with one work package that investigated human response to vi-bration, including sleep disturbance, community annoyance, and the production of a best practice guide for evaluating response. Laboratory trials at the University of Gothenburg were used to measure the effects of vibration on sleep. Physiological and psychological im-pacts of vibration exposure were found. TNO led a meta-analysis (N = 4129) to determine exposure-response relationships for railway vibration, with existing data for community re-sponse supplemented with field studies in the Netherlands and Poland. The University of Salford led production of a guidance document that presents the state of the art regarding vi-bration measurement and assessment. Specific topics in the guide include human perception, evaluation methods, annoyance, sleep impacts, and non-exposure factors. The outcomes pre-sented in this paper represent a significant advance in the understanding of the human re-sponse to railway vibration and a step towards much needed harmonization of assessment methods.
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