NWT RESEARCH DATABASE

Tags: physical sciences, permafrost, climate change, hydrology, greenhouse gases

Objective(s): To understand what factors affect the amount of carbon stored in tundra soils, and the conversion of this soil carbon into greenhouse gases (carbon dioxide and methane).

Project Description: This research aims to understand what factors affect 1) the amount of carbon stored in tundra soils, and 2) the conversion of this soil carbon into greenhouse gases (carbon dioxide and methane). In particular, the research team wants to understand how hydrology (which is the distribution and movement of water in soils and streams) might affect the carbon cycle under future global warming. This includes not only direct release of gases from the soils and plants to the atmosphere, but also the amount of carbon which moves from soils into streams as soils drain, and what happens to that carbon once in the stream water. The work will involve: 1) measuring carbon dioxide and methane production using plastic chambers. These measurements are non-destructive, and equipment will be removed from the site at the end of the project. In between weekly campaigns equipment will be stored in weatherproof aluminum boxes; 2) tracking carbon in soils and plants using a non-radioactive, naturally-occurring isotope of carbon dioxide (13CO2); 3) measuring the amount of carbon in soils, vegetation and stream water through taking samples and analysing them in the laboratory. For the soils the research team will take small cores (around 40) of approximately 5cm diameter, and a smaller number of larger diameter soil/permafrost cores for laboratory experiments (< 15cm). The research team will also dig small (20cm x 20cm) pits to examine the soil layers, which will be filled in afterwards. To sample plants the research team will clip leaves and branches in small areas (around 30, max. 20cm x 20cm); 4) monitoring soil temperatures using buried temperature sensors connected to data-recording equipment (essentially small weatherproof boxes). These will be removed at the end of the project; 5) installing 3 small V-notch weirs (essentially a piece of wooden board with a V shape cut into it which is placed across the stream and allows accurate measurement of water flow) on small streams in Sik-Sik Creek for the duration of the project. Each of these will have a sensor, data recorder and battery associated with it (in small weatherproof boxes). The sensor will be installed in a vertical 1 m long piece of narrow drain pipe in the stream. The research team will remove the sensor (but leave the pipe) over-winter. The research team will also install samplers in 0.5 m long tubes in-stream for periods of 4-6 weeks. Again the samplers will be removed before the winter sets in; and 6)marking the areas of tundra that are being sampled, so the research team can return to them the following year, using small wooden pegs/stakes. The research team will remove all markers at the end of the project, unless there is good reason to leave (some of) them in place. The research team will engage with local communities to explain the research, and in the process hopefully learn more about their perspectives on and experiences with, climate change. The research team plans to organize (with the help of our project partner Steve Kokelj) informal talks or meetings at ARI to explain the work and results. The research team would also like to have local residents visit the research site to see what is being done. The team will produce posters/information displays which can be put on view at ARI, and all scientific publications which result from the research will be archived in the library. The research team is also keen to work with local educators to provide input for (or lead) lessons or lectures on the science behind the work, for example at the local high school or Aurora College. The fieldwork for this study will be conducted from June 1, 2013 to September 6, 2013.