Active layer thermal regime at different vegetation covers at Lions Rump, King George Island, Maritime Antarctica

Almeida, Ivan Carlos Carreiro; Schaefer, Carlos Ernesto Gonçalves Reynaud; Fernandes, Raphael Bragança Alves; Pereira, Thiago Torres Costa; Nieuwendam, Alexandre; Pereira, Antônio Batista

doi:10.1016/j.geomorph.2014.03.048

Cited by 41 publications

(51 citation statements)

References 22 publications

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“…For this reason, climatic data acquired at the Brazilian Commandant Ferraz, the nearest station to Low Head, where mean monthly air temperatures vary from −6.4°C in July to +2.3°C in February, and the mean annual precipitation is 400 mm. The mean annual air temperature was − 1.1 and − 2.6°C for the years 2010 and 2011, respectively (Almeida et al, 2014). This air temperature and precipitation allows some plant growth, especially mosses, lichens and algae and the two higher plants D. antarctica and C. quitensis (Convey et al, 2011).…”

Section: Site Descriptionmentioning

confidence: 99%

“…These communities have received considerable research attention in recent years in the context of being indicators of biological responses to rapid environmental change (Parnikoza et al, 2009;Kozeretska et al, 2010) and the advanced pedogenetic processes (Simas et al, 2007;Schaefer et al, 2008;Almeida et al, 2014;Michel et al, 2014;Souza et al, 2014). However, vegetation development is highly variable at a glacier retreat zone and influenced by several soil physical (e.g., soil temperature, moisture, permafrost thawing) and biological factors (e.g., microbial community) Almeida et al, 2014). Thus, alterations on permafrost and microbial communities may drive GHG emission to the atmosphere.…”

Section: Contents Lists Available At Sciencedirectmentioning

confidence: 99%

“…Especially, the White Eagle Glacier front has retreated~500 m since 1988, exposing soil and forming new ice-free areas (Piotr and Korczak, 2010). The glacier front is at the highest elevation (94 m above sea level) and has no vegetation and low pedogenetic development (Almeida et al, 2014). Permafrost occurs at a depth of 0.96 m (on the average).…”

Section: Site Descriptionmentioning

confidence: 99%

“…This zone shows intense frost heaving and cryoturbation during the summer months. The soil is skeletal and classified as a Turbic Haploturbel (Almeida et al, 2014), with a high proportion of coarse grains (N 2 mm particles), including rock fragments (N 4 mm). The glacial retreat is proceeding along the slope, with an older exposed site at lower elevation locations (29 m above the sea).…”

Section: Site Descriptionmentioning

confidence: 99%

“…When present, the vegetation cover is composed of a mixture of lichens and mosses (Usnea sp., Sanionia uncinata) and one higher plant (D. antarctica). The soil at this retreat zone is a Typic Haplogelepts (Almeida et al, 2014).…”

Section: Site Descriptionmentioning

confidence: 99%

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CO2 and N2O emissions in a soil chronosequence at a glacier retreat zone in Maritime Antarctica

Thomazini

Mendonça

Teixeira

et al. 2015

Science of The Total Environment

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Studies of C cycle alterations are extremely important to identify changes due to climate change, especially in the polar ecosystem. The objectives of this study were to (i) examine patterns of soil CO2-C and N2O-N emissions, and (ii) evaluate the quantity and quality of soil organic matter across a glacier retreat chronosequence in the Maritime Antarctica. Field measurements were carried out during January and February 2010 (summer season) along a retreating zone of the White Eagle Glacier, at King George Island, Maritime Antarctica. Soil samples (0-10cm) were collected along a 500-m transect at regular intervals to determine changes in soil organic matter. Field CO2-C emission measurements and soil temperature were carried out at regular intervals. In addition, greenhouse gas production potentials were assessed through 100days laboratory incubations. Soils exposed for a longer time tended to have greater concentrations of soluble salts and possess sandier textures. Total organic C (3.59gkg(-1)), total N (2.31gkg(-1)) and labile C (1.83gkg(-1)) tended to be lower near the glacier front compared with sites away from it, which is correlated with decreasing degree of humification of the soil organic matter with exposure time. Soil CO2-C emissions tended to increase with distance from the glacier front. On average, the presence of vegetation increased CO2-C emissions by 440%, or the equivalent of 0.633g of CO2-C m(-2)h(-1). Results suggest that newly exposed landsurfaces undergo soil formation with increasing labile C input from vegetation, accompanied by increasing soil CO2-C emissions. Despite the importance of exposure time on CO2-C production and emissions, there was no similar trend in soil N2O-N production potentials as a function of glacial retreat. For N2O, instead, the maximum production occurred in sites with the first stages of vegetation growth.

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Section: Site Descriptionmentioning

confidence: 99%

Section: Contents Lists Available At Sciencedirectmentioning

confidence: 99%

Section: Site Descriptionmentioning

confidence: 99%

Section: Site Descriptionmentioning

confidence: 99%

Section: Site Descriptionmentioning

confidence: 99%

See 3 more Smart Citations

CO2 and N2O emissions in a soil chronosequence at a glacier retreat zone in Maritime Antarctica

Thomazini

Mendonça

Teixeira

et al. 2015

Science of The Total Environment

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Influence of soil properties on active layer thermal propagation along the western Antarctic Peninsula

Wilhelm

Bockheim

2016

Earth Surf Processes Landf

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The rate of energy transfer through soils is an important factor governing the active layer (seasonal thaw layer) in polar regions. Energy is transferred through conductive and convective means, which are primarily influenced by the bulk density and water content of soils. With global temperatures changing, it becomes important to understand how soil properties influence heat transfer and active layer depths in climatically sensitive regions, such as the Antarctic Peninsula. In this study we analyzed conductive energy transfer through several soil types on Amsler Island and Cierva Point in the central region of the western Antarctic Peninsula. Active layer temperatures on Amsler Island were monitored every three hours using iButton thermistors installed at regular depth intervals down to 2 m. Soil textures were loamy to sandy with water contents between 5 and 27%. Freezing and thawing transmission rates for all soils ranged from 1.4 to 6.9 cm/day. Thermal transmission rates were fastest in sandy soils with low water contents, indicating that the large, interconnected pores of the sandy soils facilitated the quick movement of heat with water flow through the soil profile. Snow accumulation differences also played a significant role on winter thermal propagation by providing a thermal barrier between the ground surface and atmosphere. Although there was a wide range in thermal transmission among the soils, active layer depths had little variation (7.8-9.7 m). This consistency derives from the greater dependence of very thick active layers on long-term climatic conditions rather than on soil properties. The presence of thick moss significantly slowed thermal transmission and decreased active layer thicknesses. These effects primarily are due to the high heat capacity of water and air retained within the moss, slowing thermal transmission rates, acting as a thermal buffer between atmospheric conditions and the underlying soils.

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The current response of soil thermal regime and carbon exchange of a paraglacial coastal land system in maritime Antarctica

et al. 2019

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Ice‐free areas of maritime Antarctica (MA) are undergoing rapid environmental adjustment due to climate change because glaciers retreated. In recently deglaciated areas, sensitive indicators related to soil can be used as proxies of the transition phase from glacial to nonglacial conditions at paraglacial coastal systems. This work aims at comprehending how paraglacial coastal land systems respond to adjustment processes in highly dynamic deglaciated areas, based on net ecosystem exchange, soil temperature (ST), and soil moisture (SM) temporal series in two different vegetation communities on a paraglacial coastal land system in MA. We selected a moss community (MC) and a mixed community with mosses and lichens (MLC). MC is located on a hydromorphic area with buffered ST regime, compared with MLC, where greater SM variation range and freezing conditions were observed. MC and MLC are currently acting as an atmospheric CO2 sink. In this work, MC showed a greater capacity of CO2 uptake during measurements (711.20 g CO2 m−2). In this part of Antarctica, where a recent trend of decreasing ST occurs, less permafrost and surface land degradation, combined with enhanced carbon storage, are expected. However, in the long term, following the readjustment of the paraglacial period, thawing is expected, coupled with permafrost degradation and carbon release to the atmosphere, under the predicted warming scenario in MA.

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Active layer thermal regime at different vegetation covers at Lions Rump, King George Island, Maritime Antarctica

Cited by 41 publications

References 22 publications

CO2 and N2O emissions in a soil chronosequence at a glacier retreat zone in Maritime Antarctica

CO2 and N2O emissions in a soil chronosequence at a glacier retreat zone in Maritime Antarctica

Influence of soil properties on active layer thermal propagation along the western Antarctic Peninsula

The current response of soil thermal regime and carbon exchange of a paraglacial coastal land system in maritime Antarctica

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