Joint Research Centre (JRC)

Soil Classification: Grouping soils together? An additional inside to Iceland

Rannveig Anna Guicharnaud, Arwyn Jones and Olafur Arnalds Land Resource Management Unit – Soil Action

www.jrc.ec.europa.eu ies.jrc.ec.europa.eu • Since the early 1990’s the circumpolar regions and permafrost-affected areas have become of interest – Climate change

Soil Atlas of the Northern Circumpolar Region

• The key objectives; to illustrate the importance of soil in the permafrost and seasonally frozen areas

• Special emphasis on how cold climate impact soils and the landscape

Soil Classification: Grouping soils together ?

Different definitions generate different maps

Soil classification system Cold Soils WRB Cryosols Mineral soil Permafrost 100 cm Russian System Cryozems Mineral soils Permafrost 100 cm Soil Taxonomy Gelisol Mineral and Organic Permafrost 100-200 cm Canadian System Cryosols Mineral and Organic Permafrost 100-200 cm Distribution of Cryosols – WRB organic soils are not shown on the map as they are classified separately, even if they are affected by permafrost

Arwyn Jones (2010) Distribution of Cryozems according to the Russian system – only represents permafrost affected soils, specially with intensive cryoturbation Does not include organic soils

Arwyn Jones (2010) Distribution of Gelisols – Soil Taxonomy – All permafrosts affected soils in the region including Histosols

Arwyn Jones (2010) Impact of different results – World wide implications

Due to different criteria used for mapping, estimation of global extent and hence elemental stock can be misleading Despite different classification similar geographical distribution at a global scale What about soils without cryoturbation? An example from Iceland

• Once we have agreed on how to map the regions as it is in the present, how do we deal with soils without permafrost but have intensive cryoturbation?

• Cryosols / Gelisols are recognized as specific soil order/soil group as their physical, geochemical and biochemical properties are influenced by the permafrost and cryoturbation

• Soils without permafrost can though be heavily cryoturbated as is evident from many Icelandic soils Iceland has unusually frequent freeze and thaw cycles

Orradottir et al., 2008 Number of freeze and thaw cycles

Up rooted plant

Thufur - Hummocks Palsas Þjórsárver The winter shapes the Icelandic nature

Glaciers shape Icelandic nature Cryoturbated Icelandic soils

Cryoturbation affects the soil biochemistry and hence soil the soil pedology Cryoturbation affects the soil biochemistry and hence soil the soil pedology Cryoturbation affects the soil biochemistry and hence soil the soil pedology Warming sub-soils ?

Biological changes occurred beneath a seal carcass: • Changes in the soil environment • 2 years for major changes to occur (Nature 2012; 482,278, doi:10.1038/482278a) Warming sub-soils in Iceland Korpa experimental site (SW Iceland) °C

Important changes in warming soil

• Increasing precipitation and temperature affects the soil mineralogy and geochemistry => e.g. increased weathering, leaching, plant productivity

• Increasing precipitation and temperature affects the soil biochemistry => e.g. increased microbial activity, changes in microbial communities

Frost affected soils with no permafrost

• Do we not need to classify frost affected soils without permafrost within Cryosols ????

• Should cryoturbation be taken into consideration when mapping soil erosion risk / agriculture (freeze and thaw, weak soil structure)

• Should cryoturbation be taken into account when mapping SOM changes?

• Does cryoturbation speed up biogeochemical processes compared to soils from more stable environment on the mainland? Conclusions

• National soil classification systems are needed along with one harmonized classification system such as the WRB

• Soil of the Arctic are being mapped due to their sensitivity to climate change, hence we may need to update our systems

• By e.g. including heavily cryoturbated soils in the cryosol soil group?