Well I am back in Abisko for part two of my voyage of exploration into carbon cycling at the birch forest treeline ( for first part of the voyage see below links).
The first part consisted of setting up transects from birch forest to heath sites. On these transects I have been measuring carbon dioxide gas flux in different vegetation types along with a number of different abiotic variables. Along side this I have set up long term experimental manipulations- soil transplants from forest to heath and vice versa, this is to simulate an expansion of trees and shrubs without waiting many a year for it to happen!
Anyway, the reason for this trip is to set up a leaf litter decomposition study that I have soon realised is no mean feat! The leaves in the birch forest have started to turn in colour (see below) and I am collecting them and putting them through the process of drying, weighing, putting into little nylon bags and placing them back into the field. The aim of this is to determine how much of an effect environment has on decomposition rates. Does the favourably warm winter conditions under the deep snow pack and a strong ectomycorrhizal fungi association at birch sites speed up decomposition? What are the relative effect of these two and does birch decompose faster than other leaf types in its own habitat type? All intriguing questions, all to be answered in the next couple of years when I take my ‘litter bags’ out of there sites on the tree line and re-weigh them to see how much mass the have lost through decomposition and how the chemical makeup of these leaves has changed.
This all involves a lot monotonous lab work, I have been itching to see the subarctic in autumn and I have taken my chance to at least spend some time in the field for on-going monitoring of carbon dioxide flux from my sites… with a bit of photography thrown in there….