Fundamentals of Ecohydrology (Philippe CHOLER – CNRS ... · diapo Florent Domine (LGGE) Gradients of snow cover duration Fundamentals of Ecohydrology (Philippe CHOLER – CNRS –

5. Ecology of snow covered ecosystems

Fundamentals of Ecohydrology (Philippe CHOLER – CNRS – France). Wuwei (09/2013)

Snow cover extent in the Northern Hemisphera

Fundamentals of Ecohydrology (Philippe CHOLER – CNRS – France). Wuwei (09/2013) http://climate.rutgers.edu/snowcover/

1981 - 2010

Nov. Dec. Jan.

Feb. Mar. Apr.

Couverture neigeuse continentale, février : 42 106 km2

(14% de la surface du globe)

European snow cover


Mean monthly European snow cover distribution 1967–2007

November December January

February March April

Source: Henderson G.R. & Leathers D.J. (2010) International Journal of Climatology, 30, 1440-1451.

Snow melting figures in a high watershed

Fundamentals of Ecohydrology (Philippe CHOLER – CNRS – France). Wuwei (09/2013) Source : Carlson B. (unpublished)

images Landsat 8

The main classes of seasonnal snow covers

• Snow cover shows a stratigraphy and is evolving over the season (metamorphism)

• Physical properties of the snowcover depends on its depth and itsstructure

• A simplified representation of snow is a 1-layer pack characterised by

• a temperature, Tsnow (K)• a mass, Msnow (kg m–2) • a density, ρsnow (kg m–3)


Sno

w d

epth

(cm

)

Source: Echos S.S.B., et al. (2003).

Métamorphisme du manteau neigeux


diapo Florent Domine (LGGE)

métamorphisme

Métamorphisme du manteau neigeux


diapo Florent Domine (LGGE)

Gradients of snow cover duration

Fundamentals of Ecohydrology (Philippe CHOLER – CNRS – France). Wuwei (09/2013) Source: Lafaysse M., et al. (2011) Journal of Hydrology, 403, 116-129.

Embrun

Snow vegetation interactions

• Snow, growing season length and alpine plant distribution

• Climate under the snowpack

• Biogeochemical cycling under snow


Snow cover duration & alpine plant communities

Fundamentals of Ecohydrology (Philippe CHOLER – CNRS – France). Wuwei (09/2013) Source: Choler P. (2005) Arctic Antarctic and Alpine Research, 37, 444-453.

Snow cover and alpine plant distribution

40 d. (!)

Pelouse de mode thermique à Kobresia mysoruroides (2700 m – 2750 m)

Pelouse de mode nival à Alchemilla pentaphyllea (2700 m – 2750 m)

Source: Choler P. unpublished

Snow cover duration & alpine plant strategies

Fundamentals of Ecohydrology (Philippe CHOLER – CNRS – France). Wuwei (09/2013) Source: Choler P. (2005) Arctic Antarctic and Alpine Research, 37, 444-453.

Example of snowpack temperature regime

Fundamentals of Ecohydrology (Philippe CHOLER – CNRS – France). Wuwei (09/2013) Source: Brooks P.D., et al. (2011) Geography Compass, 5, 682-699.

Snowpack light regime

Fundamentals of Ecohydrology (Philippe CHOLER – CNRS – France). Wuwei (09/2013) Source: Körner C. (1999). Springer Verlag, Berlin.

Litter mass loss under snow

Fundamentals of Ecohydrology (Philippe CHOLER – CNRS – France). Wuwei (09/2013) Source: Baptist F., et al. (2010) Plant Soil, 328, 397-410.

Microbial activity under snow


Overwinter CO2 losses Overwinter NO2 losses

Source: Brooks P.D., et al. (1997) Oecologia, 110, 403-413.

Snow cover anomalies in NH (1966-2012)

Fundamentals of Ecohydrology (Philippe CHOLER – CNRS – France). Wuwei (09/2013) http://climate.rutgers.edu/snowcover/


Reduction (in days) of winter snow cover duration in the Alps per K increase of European temperature.

Source: Hantel M. & Hirtl-Wielke L.M. (2007) International Journal of Climatology, 27, 1265-1275.

fraction of the period with snow

Projections of alpine snow cover

Fundamentals of Ecohydrology (Philippe CHOLER – CNRS – France). Wuwei (09/2013) Source: Steger C., et al. (2013) Climate Dynamics, 41, 735-754.


Increasing abundance of shrubs in the arctic

Fundamentals of Ecohydrology (Philippe CHOLER – CNRS – France). Wuwei (09/2013) Source: Sturm M., et al. (2005) Bioscience, 55, 17-26.

...and its effects on local snow redistribution

Fundamentals of Ecohydrology (Philippe CHOLER – CNRS – France). Wuwei (09/2013) Source: Sturm M., et al. (2005) Bioscience, 55, 17-26.

Shrubs and snow redistribution


Snow and subsurface temperature


Snow properties and land cover


The snow–shrub–soil–microbe feedback loop


Advanced readings

• Baptist, F., et al. 2010. Direct and indirect control by snow cover over decomposition in alpine tundra along a snowmelt gradient. - Plant Soil 328: 397-410.

• Choler, P. 2005. Consistent shifts in Alpine plant traits along a mesotopographical gradient. - Arctic Antarctic and Alpine Research 37: 444-453.

• Brooks, P. D., et al. 1996. Microbial activity under alpine snowpacks, Niwot Ridge, Colorado. - Biogeochemistry 32: 93-113; 2.

• Brooks, P. D., et al. 2011. Carbon and Nitrogen Cycling in Snow‐Covered Environments. - Geography Compass 5: 682-699.

• Hantel, M. and Hirtl-Wielke, L. M. 2007. Sensitivity of Alpine snow cover to European temperature. - International Journal of Climatology 27: 1265-1275.

• Henderson, G. R. and Leathers, D. J. 2010. European snow cover extent variability and associations with atmospheric forcings. - International Journal of Climatology 30: 1440-1451.

• Lafaysse, M., et al. 2011. Influence of spatial discretization, underground water storage and glacier melt on a physically-based hydrological model of the Upper Durance River basin. - Journal of Hydrology 403: 116-129.

• Steger, C., et al. 2013. Alpine snow cover in a changing climate: a regional climate model perspective. - Climate Dynamics 41: 735-754.

• Sturm, M., et al. 2001. Snow-shrub interactions in Arctic tundra: A hypothesis with climatic implications. - J. Clim. 14: 336-344.

• Sturm, M., et al. 2005. Winter biological processes could help convert arctic tundra to shrubland. - Bioscience 55: 17-26.


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Fundamentals of Ecohydrology (Philippe CHOLER – CNRS ... · diapo Florent Domine (LGGE) Gradients of snow cover duration Fundamentals of Ecohydrology (Philippe CHOLER – CNRS –