| 1. |
- Koehler, Birgit, 1980-, et al.
(författare)
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Inter-laboratory differences in the apparent quantum yield for the photochemical production of dissolved inorganic carbon in inland waters and implications for photochemical rate modeling
- 2022
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Ingår i: Limnology and Oceanography. - : John Wiley & Sons. - 1541-5856. ; 20:6, s. 320-337
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Tidskriftsartikel (refereegranskat)abstract
- Solar radiation initiates photochemical oxidation of dissolved organic carbon (DOC) to dissolved inorganic carbon (DIC) in inland waters, contributing to their carbon dioxide emissions to the atmosphere. Models can determine photochemical DIC production over large spatiotemporal scales and assess its role in aquatic C cycling. The apparent quantum yield (AQY) spectrum for photochemical DIC production, defined as mol DIC produced per mol chromophoric dissolved organic matter-absorbed photons, is a critical model parameter. In previous studies, the principle for the determination of AQY spectra is the same but methodological specifics differ, and the extent to which these differences influence AQY spectra and simulated aquatic DIC photoproduction is unclear. Here, four laboratories determined AQY spectra from water samples of eight inland waters that are situated in Alaska, Finland, and Sweden and span a nearly 10-fold range in DOM absorption coefficients. All AQY values fell within the range previously reported for inland waters. The inter-laboratory coefficient of variation (CV) for wavelength-integrated AQY spectra (300-450 nm) averaged 38% +/- 3% SE, and the inter-water CV averaged 63% +/- 1%. The inter-laboratory CV for simulated photochemical DIC production (conducted for the five Swedish lakes) averaged 49% +/- 12%, and the inter-water CV averaged 77% +/- 10%. This uncertainty is not surprising given the complexities and methodological choices involved in determining DIC AQY spectra and needs to be considered when applying photochemical rate modeling. Thus, we also highlight current methodological limitations and suggest future improvements for DIC AQY determination to reduce inter-laboratory uncertainty.
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| 2. |
- Lehikoinen, Aleksi, et al.
(författare)
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Rapid climate driven shifts in wintering distributions of three common waterbird species
- 2013
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Ingår i: Global Change Biology. - : Wiley. - 1354-1013. ; 19:7, s. 2071-2081
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Tidskriftsartikel (refereegranskat)abstract
- Climate change is predicted to cause changes in species distributions and several studies report margin range shifts in some species. However, the reported changes rarely concern a species' entire distribution and are not always linked to climate change. Here, we demonstrate strong north-eastwards shifts in the centres of gravity of the entire wintering range of three common waterbird species along the North-West Europe flyway during the past three decades. These shifts correlate with an increase of 3.8 degrees C in early winter temperature in the north-eastern part of the wintering areas, where bird abundance increased exponentially, corresponding with decreases in abundance at the south-western margin of the wintering ranges. This confirms the need to re-evaluate conservation site safeguard networks and associated biodiversity monitoring along the flyway, as new important wintering areas are established further north and east, and highlights the general urgency of conservation planning in a changing world. Range shifts in wintering waterbirds may also affect hunting pressure, which may alter bag sizes and lead to population-level consequences.
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