Erosion, Evasion and Ecosystem Exchange – Which is most significant for the Falklands peatland carbon balance?

Katy Ross

Carbon is constantly being cycled through terrestrial and aquatic systems however many peatlands around the world are out of balance, no longer a carbon sink they are releasing gasses which contribute to climate change, often as a direct result of human land management. In this article Katy discusses her research in terms of pathways of carbon loss and the relative contributions of each of these in a Falklands context.
Image: Falkalnds Landscape
Peatlands are widely quoted as one of the most important terrestrial carbon stores on the planet; however many are now net sources of carbon, often as a result of drying due to changing land management.

While loss via gaseous exchange, such as carbon dioxide and methane release are often the most understood, there are many mechanisms by which this carbon can be lost from peatlands. In the Falklands, with its total peatland carbon stock of around 934 Mt C (Upson et al. 2006) it is estimated that 0.05 Mt C is lost each year as it is dissolved into waterways around the islands (Bax et al. 2022). This carbon can be released back into the atmosphere through evasion, where carbon dioxide is degassed from rivers.

Ecosystem exchange considers the loss or gain of carbon through photosynthesis and respiration and is thought to be in the region of 1,149,326 t CO2e yr-1 (Evans et al. 2020) for the Falkland Islands. Throughout her PhD Katy is looking to add to the data contributing to this figure by carrying out measurements of greenhouse gas exchange from peatlands across the Falklands. However, over the past few months she has also been trying to measure the loss of material through erosion. By setting up sampling traps known as ‘Big Spring Number 8’s’ she has been able to quantify the mass of particulate matter moving through the air at several sites.
Image left: A Big Spring Number 8 or BSNE used to collect wind-blown peat to try and get estimates of erosion from across the Falklands. 
Some of these results are already astounding. The mass of peat moving across the Falklands is several orders of magnitude higher than for agricultural fen peatlands in Cambridgeshire and suggests that erosion, rather than ecosystem exchange may be a key consideration in future carbon offsetting schemes. The next challenge is working out why erosion is so much higher in the Falklands than for other peatlands.

This has involved instrumenting the Falklands with sonic anenometers and soil moisture loggers to try and determine which environmental factors give rise to the highest rates of erosion. By looking at wind speeds and soil moisture and the interaction between the two Katy hopes to determine the times of the year which pose the most significant risks for erosion whilst working out how restoration measures may reduce the loss.
Image above: The peat samples from the BSNE’s are put in a furnace once they have been dried and weighed. By heating them to a high temperature, you burn off any organic matter and can then work out the carbon content of the peat. In this picture are the ashy remains of samples.
Image above: By measuring wind and soil moisture Katy is hoping to work out which environmental factors are most significant in contributing to erosion

She is hoping to give a talk on some of her early results soon. In the mean time you can watch how she measures greenhouse gases in SAERI’s time-lapse video. If you want to hear more about the project or get involved contact katros@ceh.ac.uk or follow along with her research on Twitter at @girl_in_a_bog

Collaborators on the project include the Centre for Ecology and Hydrology, the University of Leicester and the Natural History Museum. Katy's PhD supervisors include Dr Steffi Carter, Prof Chris Evans, Prof Sue Page, Dr Anne Jungblut, Dr Arnoud Boom and Dr Ross Morrison. And a huge thank you to local sponsors Georgia Seafoods

 

References: 

Upson R., McAdam J., Clubbe C. (2016). Climate Change Risk Assessment for Plants and Soils of the Falkland Islands and the Services They Provide (Royal Botanic Gardens Kew and UK Falkland Islands Trust). doi: 10.13140/RG.2.2.15660.67203

Bax, N., Barnes, D. K., Pineda-Metz, S. E., Pearman, T., Diesing, M., Carter, S., ... & Bayley, D. T. (2022). Towards incorporation of blue carbon in Falkland Islands marine spatial planning: a multi-tiered approach. Frontiers in Marine Science, 9.

Evans, C. et al (2020). A scoping study for potential community-based carbon offsetting schemes in the Falkland Islands. Report to Falklands Conservation, Stanley

FALKLAND ISLANDS OFFICE:
PO Box 609, Stanley Cottage North
Ross Road, Falkland Islands
Stanley, FIQQ 1ZZ
Falkland Islands: +500 27374
UK Office: +44 (0)203 745 1731
© Copyright 2022 - SAERI
envelopephone-handsetmap-marker linkedin facebook pinterest youtube rss twitter instagram facebook-blank rss-blank linkedin-blank pinterest youtube twitter instagram