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Abstract Pyrogenic organic residues from wildfires and anthropogenic combustion are ubiquitous in the environment and susceptible to leaching from soils into rivers, where they are known as dissolved black carbon (DBC). Here we quantified and isotopically characterized DBC from the second largest river on Earth, the Congo, using 12 samples collected across three annual hydrographs from 2010 to 2012. We find that the Congo River exports an average of 803 ± 84 Gg‐C as DBC per year, comprising 7.5% of the river's average annual dissolved organic carbon (DOC) flux (10.7 ± 1.2 Tg‐C yr−1). Concentrations of DBC were strongly correlated with discharge and DOC concentration, indicating transport limitation for DBC flux from the Congo River Basin. Stable carbon isotopic signatures of DBC revealed a seasonal shift in pyrogenic source from forest dominant to an increasing contribution from savannah biomass, which derives from the North‐South bimodal hydrologic regime within the basin. Our results also indicate that black carbon produced within the Congo Basin is exported by the river on relatively short time scales and that total DBC export will increase with climate change predictions for the central African region.
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This content will become publicly available on May 8, 2026
The Nucras (Squamata: Lacertidae) of the eastern Zambezi River Basin, with the description of a new species from Zambia
The Nucras of the eastern Zambezi River basin region, comprising Zambia, Malawi and central Mozambique have been poorly studied. We re-evaluated the type specimens of Lacerta cameranoi Bedriaga, 1886 and L. tessellata pseudotessellata Bedriaga, 1886, both collected at Tete, Mozambique by Wilhelm Peters in the 1840s. Both are assignable to N. ornata, the most widespread Nucras in the region. However, an additional specimen collected from Tete is referrable to N. holubi, filling a collecting gap for this species between central Zimbabwe and southern Malawi. Nucras records from northeastern Zambia include several N. boulengeri, two photo-vouchered records, one unidentifiable and the other an enigmatic form not consistent with any known species, and a new species from Senga Hill, Northern Province. The new species, Nucras margaritae sp. nov., is known only from its holotype. It is morphologically similar to N. ornata, from which it is separated by 620 airline km, but is deeply genetically divergent from all congeners and is sister to the clade comprising N. holubi, N. ornata, N. damarana and N. intertexta. At least five species of Nucras, four currently named, inhabit the greater eastern Zambezi River basin.
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- Award ID(s):
- 2146654
- PAR ID:
- 10588743
- Publisher / Repository:
- Magnolia Press
- Date Published:
- Journal Name:
- Zootaxa
- Volume:
- 5632
- Issue:
- 3
- ISSN:
- 1175-5326
- Page Range / eLocation ID:
- 480 to 500
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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