| 1. |
- Kaufman, Darrell, et al.
(author)
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A global database of Holocene paleotemperature records
- 2020
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In: Scientific Data. - : Springer Science and Business Media LLC. - 2052-4463. ; 7:1
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Journal article (peer-reviewed)abstract
- A comprehensive database of paleoclimate records is needed to place recent warming into the longer-term context of natural climate variability. We present a global compilation of quality-controlled, published, temperature-sensitive proxy records extending back 12,000 years through the Holocene. Data were compiled from 679 sites where time series cover at least 4000 years, are resolved at sub-millennial scale (median spacing of 400 years or finer) and have at least one age control point every 3000 years, with cut-off values slackened in data-sparse regions. The data derive from lake sediment (51%), marine sediment (31%), peat (11%), glacier ice (3%), and other natural archives. The database contains 1319 records, including 157 from the Southern Hemisphere. The multi-proxy database comprises paleotemperature time series based on ecological assemblages, as well as biophysical and geochemical indicators that reflect mean annual or seasonal temperatures, as encoded in the database. This database can be used to reconstruct the spatiotemporal evolution of Holocene temperature at global to regional scales, and is publicly available in Linked Paleo Data (LiPD) format.
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| 2. |
- Rademacher, Peter, et al.
(author)
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European co-operation in wood research From native wood to engineered materials : Part 2: densification modification in product development
- 2017
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In: Pro Ligno. - Romania : Pro Ligno Foundation. - 1841-4737 .- 2069-7430. ; 13:4, s. 351-360
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Journal article (peer-reviewed)abstract
- Wood is a renewable, biological material used in numerous applications and it is growing in importance due to sustainable development efforts. Wood also suffers from a number of disadvantages, were low hardness and abrasive resistance are characteristic for low-density species. This paper presents state of the art on different wood densification processes as one emerging process technology for increased use of low-density species. The presentation is based on work by different European research groups in wood science, collaborating in the field mainly through different COST Actions. The main principles for processes are discussed, such as bulk and surface densification, as well as methods for reducing the shape memory effect of densified wood. The main challenges for the future are in the field of finding fast and environmental friendly method for elimination of the set-recovery and scaling up to profitable industrial applications. To provide a better understanding with this regard, some relevant applications of densified wood are presented.
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| 3. |
- Shumilova, Oleksandra, et al.
(author)
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Simulating rewetting events in intermittent rivers and ephemeral streams : A global analysis of leached nutrients and organic matter
- 2019
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In: Global Change Biology. - : WILEY. - 1354-1013 .- 1365-2486. ; 25:5, s. 1591-1611
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Journal article (peer-reviewed)abstract
- Climate change and human pressures are changing the global distribution and the extent of intermittent rivers and ephemeral streams (IRES), which comprise half of the global river network area. IRES are characterized by periods of flow cessation, during which channel substrates accumulate and undergo physico-chemical changes (preconditioning), and periods of flow resumption, when these substrates are rewetted and release pulses of dissolved nutrients and organic matter (OM). However, there are no estimates of the amounts and quality of leached substances, nor is there information on the underlying environmental constraints operating at the global scale. We experimentally simulated, under standard laboratory conditions, rewetting of leaves, riverbed sediments, and epilithic biofilms collected during the dry phase across 205 IRES from five major climate zones. We determined the amounts and qualitative characteristics of the leached nutrients and OM, and estimated their areal fluxes from riverbeds. In addition, we evaluated the variance in leachate characteristics in relation to selected environmental variables and substrate characteristics. We found that sediments, due to their large quantities within riverbeds, contribute most to the overall flux of dissolved substances during rewetting events (56%-98%), and that flux rates distinctly differ among climate zones. Dissolved organic carbon, phenolics, and nitrate contributed most to the areal fluxes. The largest amounts of leached substances were found in the continental climate zone, coinciding with the lowest potential bioavailability of the leached OM. The opposite pattern was found in the arid zone. Environmental variables expected to be modified under climate change (i.e. potential evapotranspiration, aridity, dry period duration, land use) were correlated with the amount of leached substances, with the strongest relationship found for sediments. These results show that the role of IRES should be accounted for in global biogeochemical cycles, especially because prevalence of IRES will increase due to increasing severity of drying events.
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