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Maritime Antarctica has a milder climate than the Antarctic continent and is naturally more sensitive to rising global temperature. Therefore, it is necessary to understand the soils, including those with permafrost, as well as the relief and the occurrence of organic carbon at Byers Peninsula. This study aims therefore to investigate soil physical and chemical properties at Byers Peninsula, Maritime Antarctica, in particular, the distribution of organic carbon. Thirteen soil profiles were described, collected, and subjected to a physical, chemical, and spatial analysis. Colonization by avifauna and vegetation is important for inputing soil organic carbon at Byers Peninsula. Cryoturbation and permafrost are crucialforthe redistribution of the C pool. Distribution of organic carbon on the Byers Peninsula have shown that its concentrations are higher and more punctual at the surface, but also that carbon has been redistributed to deeper layers. Gelisols (Cryosols) are important C pools. They are extremely useful from the environmental monitoring perspective as they represent areas sensitive to temperature increases on the Antarctic Peninsula caused by global climate changes. Using geomorphological groups is one way to improve the understanding of these relief forms, soil and rocktypes, vegetation patterns, and the presence of permafrost.

期刊论文 2025-01-01 DOI: 10.1590/0001-3765202520240310 ISSN: 0001-3765

Ice-free areas occupy 5 m in bedrock sites in the Antarctic Peninsula. The deepest and most variable ALTs (ca. 40 to >500 cm) were found in the Antarctic Peninsula, whereas the maximum ALT generally did not exceed 90 cm in Victoria Land and East Antarctica. Notably, found that the mean annual near-surface temperature follows the latitudinal gradient of-0.9 degrees C/deg. (R2 = 0.9) and the active layer thickness 3.7 cm/deg. (R2 = 0.64). The continuous permafrost occurs in the vast majority of the ice-free areas in Antarctica. The modelling of temperature on the top of the permafrost indicates also the permafrost presence in South Orkneys and South Georgia. The only areas where deep boreholes and geophysical surveys indicates discontinuous or sporadic permafrost are South Shet-lands and Western Antarctic Peninsula.

期刊论文 2023-07-01 DOI: 10.1016/j.earscirev.2023.104458 ISSN: 0012-8252

Permafrost (perennially frozen) soils store vast amounts of organic carbon (C) and nitrogen (N) that are vulnerable to mobilization as dissolved organic carbon (DOC) and dissolved organic and inorganic nitrogen (DON, DIN) upon thaw. Such releases will affect the biogeochemistry of permafrost regions, yet little is known about the chemical composition and source variability of active-layer (seasonally frozen) and permafrost soil DOC, DON and DIN. We quantified DOC, total dissolved N (TDN), DON, and DIN leachate yields from deep active-layer and near-surface boreal Holocene permafrost soils in interior Alaska varying in soil C and N content and radiocarbon age to determine potential release upon thaw. Soil cores were collected at three sites distributed across the Alaska boreal region in late winter, cut in 15 cm thick sections, and deep active-layer and shallow permafrost sections were thawed and leached. Leachates were analyzed for DOC, TDN, nitrate (NO3-), and ammonium (NH4+) concentrations, dissolved organic matter optical properties, and DOC biodegradability. Soils were analyzed for C, N, and radiocarbon (C-14) content. Soil DOC, TDN, DON, and DIN yields increased linearly with soil C and N content, and decreased with increasing radiocarbon age. These relationships were significantly different for active-layer and permafrost soils such that for a given soil C or N content, or radiocarbon age, permafrost soils releasedmore DOC and TDN (mostly as DON) per gram soil than active-layer soils. Permafrost soil DOC biodegradability was significantly correlated with soil Delta C-14 and DOM optical properties. Our results demonstrate that near-surface Holocene permafrost soils preserve greater relative potential DOC and TDN yields than overlying seasonally frozen soils that are exposed to annual leaching and decomposition. While many factors control the fate of DOC and TDN, the greater relative yields from newly thawed Holocene permafrost soils will have the largest potential impact in areas dominated by organic-rich soils.

期刊论文 2018-06-01 DOI: 10.1088/1748-9326/aac4ad ISSN: 1748-9326
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