High Arctic Biocomplexity Research - Thule, Greenland
High Arctic Soil Science
Pit dug in fen area of Dundas Valley.
Note organics frozen in permafrost
at the bottom.
The response of High Arctic ecosystems to global climate change requires that we have a better understanding of terrestrial organic carbon dynamics and distribution. To forecast the potential feedback of soil carbon in an anthropogenically warmed environment, it is important to have good estimates of the existing quantity and quality of carbon stores in the arctic. Various methods have been used toward this goal including; remote sensing, carbon dioxide flux measurements, soil pits and transects, biomass estimates, and others. While each has its merits, none has been able to confidently assess the total soil carbon (to the top of the permafrost) for the High (or Low) Arctic.
Field assistant Andrew excavates a pit in a
carbonate rich region of South Mountain.
We are developing a multidisciplinary approach to more completely estimate soil organic carbon stores. This approach combines remote sensing, vegetation classification, soil science, geochemistry, correlation studies, and geomorphology in a multi-year research project at the Thule Air Base in Greenland . A major focus of the field campaign thus far has been the collection of geographically and geologically distinct soil samples from pits dug to the top of the frost table in permafrost soils across the Thule peninsular region. In 2004, 34 pits were dug in regions of differing vegetation abundance, geologic substrates, elevation, and moisture conditions. Pit depths ranged from 40-95 cm . This often, but not always was limited by permafrost depth. Processing of soil samples for organic carbon content, particle size analysis, stable isotopes, and 14C dates will begin in the fall of 2004.
The pictures below are from a 16m long trench that was dug perpendicular to vegetated "stripes" on South Mountain. This provided an exciting opportunity for collaborative research on the formation of this patterned ground feature.
The 3 PIs examine the trench
Stripe site on South Mountain prior to trenching.
Close up view of "wave" structures
visible at the base of the trench.
Jennifer and Andrew doing fine scale cleaning of the trench.
Remote Sensing and Soil Carbon Mapping
Joe DeCant uses an NDVI camera
to take pictures of satellite control plots.
Jennifer using a GPS device to locate pre-selected sites.
The use of remotely sensed data of the study area has provided a wonderful tool for planning and mapping during the 2004 field season. The following maps provide some information on the techniques used.