Roundup: GLOFs, Iron, and Soil Stability

Roundup: GLOFs, Iron, and Soil

 

Observations of a GLOF near Mt. Everest

From The Cryosphere: “Glacier outburst floods with origins from Lhotse Glacier, located in the Everest region of Nepal, occurred on 25 May 2015 and 12 June 2016. The most recent event was witnessed by investigators, which provided unique insights into the magnitude, source, and triggering mechanism of the flood. The field assessment and satellite imagery analysis following the event revealed that most of the flood water was stored englacially and that the flood was likely triggered by dam failure.”

Read more about the GLOF events in Nepal here.

Image of a GLOF from the Lhotse Glacier in June 2016 (Source: Caroline Clasoni/Twitter).

 

Transfer of Iron to the Antarctic

From Nature: “Iron supplied by glacial weathering results in pronounced hotspots of biological production in an otherwise iron-limited Southern Ocean Ecosystem. However, glacial iron inputs are thought to be dominated by icebergs. Here we show that surface runoff from three island groups of the maritime Antarctic exports more filterable than icebergs. Glacier-fed streams also export more acid-soluble iron associated with suspended sediment than icebergs. Significant fluxes of filterable and sediment-derived iron are therefore likely to be delivered by runoff from the Antarctic continent. Although estuarine removal processes will greatly reduce their availability to coastal ecosystems, our results clearly indicate that riverine iron fluxes need to be accounted for as the volume of Antarctic melt increases in response to 21st century climate change.”
Learn more about iron transfer here.
Iron ore on an Antarctic glacier (Source: jpfitz/Twitter).

 

The Role of Vegetation in Alpine Soil Stability

From International Soil and Water Conservation Research: “One fifth of the world’s population is living in mountains or in their surrounding areas. This anthropogenic pressure continues to grow with the increasing number of settlements, especially in areas connected to touristic activities, such as the Italian Alps. The process of soil formation on high mountains is particularly slow and these soils are particularly vulnerable to soil degradation. In alpine regions, extreme meteorological events are increasingly frequent due to climate change, speeding up the process of soil degradation and increasing the number of severe erosion processes, shallow landslides and debris flows. Vegetation cover plays a crucial role in the stabilization of mountain soils thereby reducing the risk of natural hazards effecting downslope areas.”
Read more about soil stability here.
Vegetation on Mount Rainier (Source: National Park Service).

Roundup: Carbon Sinks, Serpentine Syndrome and Migration Dynamics

Roundup: Carbon, Serpentine, and Migration

 

Dwindling Glaciers Lead to Potential Carbon Sinks

From PLOS ONE: “Current glacier retreat makes vast mountain ranges available for vegetation establishment and growth. As a result, carbon (C) is accumulated in the soil, in a negative feedback to climate change. Little is known about the effective C budget of these new ecosystems and how the presence of different vegetation communities influences CO2 fluxes. On the Matsch glacier forefield (Alps, Italy) we measured over two growing seasons the Net Ecosystem Exchange (NEE) of a typical grassland, dominated by the C3 Festuca halleri All., and a community dominated by the CAM rosettes Sempervivum montanum L… The two communities showed contrasting GEE but similar Reco patterns, and as a result they were significantly different in NEE during the period measured. The grassland acted as a C sink, with a total cumulated value of -46.4±35.5 g C m-2 NEE, while the plots dominated by the CAM rosettes acted as a source, with 31.9±22.4 g C m-2. In spite of the different NEE, soil analysis did not reveal significant differences in carbon accumulation of the two plant communities, suggesting that processes often neglected, like lateral flows and winter respiration, can have a similar relevance as NEE in the determination of the Net Ecosystem Carbon Balance.”

Learn more about the colonization of a deglaciated moraine here.

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Glacier National Park (Source: Ada Be/Flickr).

 

Vegetation and the Serpentine Syndrome

From Plant and Soil: “Initial stages of pedogenesis (soil formation) are particularly slow on serpentinite (a dark, typically greenish metamorphic rock that weathers to form soil). This implies a slow accumulation of available nutrients and leaching of phytotoxic (poisonous to plants) elements. Thus, a particularly slow plant primary succession should be observed on serpentinitic proglacial areas. The observation of soil-vegetation relationships in such environments should give important information on the development of the serpentine syndrome (a phrase to explain plant survival on serpentine)… Plant-soil relationships have been statistically analysed, comparing morainic environments on pure serpentinite and serpentinite with small sialic inclusions in the North-western Italian Alps….Pure serpentinite supported strikingly different plant communities in comparison with the sites where the serpentinitic till was enriched by small quantities of sialic rocks.”

Find out more about the serpentine syndrome here.

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Franz Josef Glacier, New Zealand (Source: André Pipa/Flickr).

 

Climate Changes Landscape of South American Communities

From Global Migration Issues: “Mountain regions are among the most vulnerable areas with regard to global environmental changes. In the Bolivian Andes, for example, environmental risks, such as those related to climate change, are numerous and often closely intertwined with social risks. Rural households are therefore characterized by high mobility, which is a traditional strategy of risk management. Nowadays, most rural households are involved in multi-residency or circular migratory movements at a regional, national, and international scale. Taking the case of two rural areas close to the city of La Paz, we analyzed migration patterns and drivers behind migrant household decisions in the Bolivian Andes… Our results underline that migration is a traditional peasant household strategy to increase income and manage livelihood risks under rising economic pressures, scarcity of land, insufficient local off-farm work opportunities, and low agricultural productivity… Our results suggest that environmental factors do not drive migration independently, but are rather combined with socio-economic factors.”

Read more about migration dynamics here.

View of the Bolivian Andes and the city of La Paz (Source: Cliff Hllis/Flickr).
View of the Bolivian Andes and the city of La Paz (Source: Cliff Hellis/Flickr).