| 1. |
- Tye, Andrew M., et al.
(författare)
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Dissolved inorganic carbon export from rivers of Great Britain : Spatial distribution and potential catchment-scale controls
- 2022
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Ingår i: Journal of Hydrology. - : Elsevier. - 0022-1694 .- 1879-2707. ; 615
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Tidskriftsartikel (refereegranskat)abstract
- Dissolved inorganic carbon (DIC) fluxes from the land to ocean have been quantified for many rivers globally. However, CO2 fluxes to the atmosphere from inland waters are quantitatively significant components of the global carbon cycle that are currently poorly constrained. Understanding, the relative contributions of natural and human-impacted processes on the DIC cycle within catchments may provide a basis for developing improved management strategies to mitigate free CO2 concentrations in rivers and subsequent evasion to the atmosphere. Here, a large, internally consistent dataset collected from 41 catchments across Great Britain (GB), accounting for ∼36% of land area (∼83,997 km2) and representative of national land cover, was used to investigate catchment controls on riverine dissolved inorganic carbon (DIC), bicarbonate (HCO3−) and free CO2 concentrations, fluxes to the coastal sea and annual yields per unit area of catchment. Estimated DIC flux to sea for the survey catchments was 647 kt DIC yr−1 which represented 69% of the total dissolved carbon flux from these catchments. Generally, those catchments with large proportions of carbonate and sedimentary sandstone were found to deliver greater DIC and HCO3− to the ocean. The calculated mean free CO2 yield for survey catchments (i.e. potential CO2 emission to the atmosphere) was 0.56 t C km−2 yr−1. Regression models demonstrated that whilst river DIC (R2 = 0.77) and HCO3− (R2 = 0.77) concentrations are largely explained by the geology of the landmass, along with a negative correlation to annual precipitation, free CO2 concentrations were strongly linked to catchment macronutrient status. Overall, DIC dominates dissolved C inputs to coastal waters, meaning that estuarine carbon dynamics are sensitive to underlying geology and therefore are likely to be reasonably constant. In contrast, potential losses of carbon to the atmosphere via dissolved CO2, which likely constitute a significant fraction of net terrestrial ecosystem production and hence the national carbon budget, may be amenable to greater direct management via altering patterns of land use.
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| 2. |
- Williamson, Jennifer L., et al.
(författare)
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Landscape controls on riverine export of dissolved organic carbon from Great Britain
- 2021
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Ingår i: Biogeochemistry. - : Springer Science and Business Media LLC. - 0168-2563 .- 1573-515X.
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Tidskriftsartikel (refereegranskat)abstract
- The dissolved organic carbon (DOC) export from land to ocean via rivers is a significant term in the global C cycle, and has been modified in many areas by human activity. DOC exports from large global rivers are fairly well quantified, but those from smaller river systems, including those draining oceanic regions, are generally under-represented in global syntheses. Given that these regions typically have high runoff and high peat cover, they may exert a disproportionate influence on the global land–ocean DOC export. Here we describe a comprehensive new assessment of the annual riverine DOC export to estuaries across the island of Great Britain (GB), which spans the latitude range 50–60° N with strong spatial gradients of topography, soils, rainfall, land use and population density. DOC yields (export per unit area) were positively related to and best predicted by rainfall, peat extent and forest cover, but relatively insensitive to population density or agricultural development. Based on an empirical relationship with land use and rainfall we estimate that the DOC export from the GB land area to the freshwater-seawater interface was 1.15 Tg C year−1 in 2017. The average yield for GB rivers is 5.04 g C m−2 year−1, higher than most of the world’s major rivers, including those of the humid tropics and Arctic, supporting the conclusion that under-representation of smaller river systems draining peat-rich areas could lead to under-estimation of the global land–ocean DOC export. The main anthropogenic factor influencing the spatial distribution of GB DOC exports appears to be upland conifer plantation forestry, which is estimated to have raised the overall DOC export by 0.168 Tg C year−1. This is equivalent to 15% of the estimated current rate of net CO2 uptake by British forests. With the UK and many other countries seeking to expand plantation forest cover for climate change mitigation, this ‘leak in the ecosystem’ should be incorporated in future assessments of the CO2 sequestration potential of forest planting strategies.
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| 5. |
- Gerlach, Joe, et al.
(författare)
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Geophilosophy round table
- 2023
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Ingår i: Subjectivity. - : Springer. - 1755-6341 .- 1755-635X.
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- This round table originated in an online discussion to launch the Geophilosophy Special Issue, held on 14th December 2022. In what follows, Joe Gerlach offers an extended commentary on each of the papers, with responses from the contributors to the Special Issue.
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| 6. |
- Williams, Nina, et al.
(författare)
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Practising post-humanism in geographical research
- 2019
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Ingår i: Transactions of the Institute of British Geographers. - : Wiley-Blackwell Publishing Inc.. - 0020-2754 .- 1475-5661. ; 44:4, s. 637-643
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Tidskriftsartikel (refereegranskat)abstract
- Post-humanist theories shaping contemporary geographic research have unsettled the privileged position of the “human” as a common reference to apprehend social life. This decentring of the human demands that we rethink our expectations of, and approaches to, methodological practice and the traditional distinctions made between the theoretical and the empirical. In this introduction and the following interventions, we explore how a material situatedness and attention to nonhuman agencies within post-humanist thought complement and extend existing methodological innovations within human geography. We do so with reference to a series of Masters workshops – a somewhat overlooked space of research-creation – each of which explored the implications of post-humanism on methodological practice. The introduction concludes with three key tenets that were followed in each of the individual workshops, and which set out an ethos for practising post-humanism more broadly.
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