Roundup: Siberia, Serpentine and Seasonal Cycling

Posted by on Jan 16, 2017

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Roundup: Siberian Glaciers, Vegetation Succession and Sea Ice

 

Glaciers in Siberia During the Last Glacial Maximum

From Palaeogeography, Palaeoclimatology, Palaeoecology: “It is generally assumed that during the global Last Glacial Maximum (gLGM, 18–24 ka BP) dry climatic conditions in NE Russia inhibited the growth of large ice caps and restricted glaciers to mountain ranges. However, recent evidence has been found to suggest that glacial summers in NE Russia were as warm as at present while glaciers were more extensive than today… We hypothesize that precipitation must have been relatively high in order to compensate for the high summer temperatures… Using a degree-day-modelling (DDM) approach, [we] find that precipitation during the gLGM was likely comparable to, or even exceeded, the modern average… Results imply that summer temperature, rather than aridity, limited glacier extent in the southern Pacific Sector of NE Russia during the gLGM.”

Read more about the study here.

 

Siberia experiences very cold temperatures but has relatively few glaciers (Source: Creative Commons)

Siberia experiences very cold temperatures but has relatively few glaciers (Source: Creative Commons).

 

Plant Communities in the Italian Alps

From Plant and Soil: “Initial stages of pedogenesis (soil formation) are particularly slow on serpentinite… Thus, a particularly slow plant primary succession should be observed on serpentinitic proglacial (in front of glaciers) areas..Ssoil-vegetation relationships in such environments should give important information on the development of the “serpentine syndrome” .Pure serpentinite supported strikingly different plant communities in comparison with the sites where the serpentinitic till was enriched by small quantities of sialic (rich in silica and aluminum) rocks. While on the former materials almost no change in plant species composition was observed in 190 years, four different species associations were developed with time on the other. Plant cover and biodiversity were much lower on pure serpentinite as well.”

Read more about “serpentine syndrome” here.

 

Plant communities in the Italian Alps can differ depending on the underlying bed rock (Source: Creative Commons)

Plant communities in the Italian Alps can differ depending on the underlying bed rock (Source: Creative Commons).

 

Carbon Cycling and Sea Ice in Ryder Bay

From Deep Sea Research Part II: Topical Studies in Oceanography: “The carbon cycle in seasonally sea-ice covered waters remains poorly understood due to both a lack of observational data and the complexity of the system… We observe a strong, asymmetric seasonal cycle in the carbonate system, driven by physical processes and primary production. In summer, melting glacial ice and sea ice and a reduction in mixing with deeper water reduce the concentration of dissolved organic carbon (DIC) in surface waters… In winter, mixing with deeper, carbon-rich water and net heterotrophy increase surface DIC concentrations… The variability observed in this study demonstrates that changes in mixing and sea-ice cover significantly affect carbon cycling in this dynamic environment.”

Read more about carbon cycling in West Antarctica here.

 

Seasonal sea ice melting influences the cycling of carbon in West Antarctica (Source: Jason Auch / Creative Commons).

Seasonal sea ice melting influences the cycling of carbon in West Antarctica (Source: Jason Auch/Creative Commons).

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