Friday, 14 March 2014

Wool sampling spring/summer 2014

In my research, I study the composition of samples of archaeological sheep wool to find out where they come from. In order to be able to read the data from the past, I need to have equivalent data from now. That means I also analyse modern wool samples from the same regions. During my PhD, I worked on understanding textiles from the UK and Iceland. Now, as a postdoc, I am extending this approach to Scandinavia and the countries round the Baltic.

In 2013, I contacted sheep farmers' organisations in Norway, Denmark and Sweden. I asked them to put me in touch with farmers who wanted to send me wool for this project. One farmer in Denmark, two in Sweden and five in Norway very generously answered my request and sent me samples from their flocks. In total, almost a hundred samples, which is very good indeed - thank you VERY much!

Relief map of Scandinavia and the Baltic Sea region, with sampled farm locations indicated. Background image source
This year I am extending sampling towards the east, to get wool from Finland, Estonia, Latvia, Lithuania, Poland as well as from here in Germany. I am also keen to get samples from mountainous and inland areas of Norway and Sweden. Mountain environments are likely to be different from coastal ones, both in vegetation and in farming practice, so this would be isotopically very interesting. 

I have contacted sheep-farming organisations in all these countries again this year. I am looking for samples from sheep which are being kept in a 'traditional' manner, that is without concentrate feeds, on unfertilized pasture, and with hay supplementation from the local area only, with or without transhumance to altitude during the summer. Samples are taken at clipping to minimise work required. 

Can you help me with this project? I'd love to hear from you! Email

Sheep of the month - March 2014

Cattle and sheep in mixed grazing. Image: Susan Schoenian 
Species notes
Domesticated herbivores consume plants differently. Cattle predominantly eat grass, with some weeds and bush/shrub leaves. Sheep eat more weeds, and can be successfully kept on shorter, less mature grass than cows. Goats prefer to browse on leaves. This means that different species can be grazed in the same area (either all at once or at different times in the year) as they will not eat the same plants. This can reduce the chance of damaging the pasture by over-grazing. However farmers have to consider the potential for disease/parasite transmission between species. More info:

Isotope notes
Plants differ in isotope composition because of differences in their metabolism. The most important factors are their photosynthetic mechanism (C3/C4/CAM), nitrogen fixing ability (root microbe symbiosis type) and water-use efficiency (transpiration rate). This last can also differ strongly between different parts of the same plant, and between seasons as humidity and temperature change. Therefore, different domesticated herbivores grazing on the same pasture may consume diets which are different isotopically.