Using coprophilous fungal spores to detect abandoned reindeer milking sites in northern Sweden

Reindeer (Rangifer tarandus) is the single most dominant large herbivore affecting the vegetation of the northern Fennoscandia. It has been observed throughout the Arctic, and especially in Fennoscandia and northern Russia that combined human-animal agency, e.g. concentrated grazing and trampling by semi-domesticated reindeer herds, has changed the vegetation by creating graminoid-dominated green patches, which may persist for centuries. The warming that has taken in recent decades has driven vegetation changes in these areas, especially by increasing erect deciduous shrub growth and it remains to be seen if these lawns will persist further. Two sites, Suollagavallda and Viejevágge, located in the Swedish Scandes Mountains, were chosen for a high-resolution pollen and coprophilous fungal spore analysis. Both sites are in mountain valleys with numerous dwellings which are up to 1000 years old. Ancient dwellings are indicated by rows of hearths and circular depressions on the ground. Sami have traditionally practiced reindeer milking in the area from the middle of the summer until autumn, and the animals have been kept on site for some weeks at the time, year after year repeatedly over several generations, which has had a noticeable effect on the vegetation structure, cover, and composition. Recent studies from the Netherlands show that there is a highly significant relationship between the coprophilous fungal spore abundance and local biomass densities of herbivores that can be used in the calibration of fossil records. The aim of this study is to use the coprophilous fungal spores to detect the local presence of reindeer and the timing and duration of the reindeer milking in the area. The initial results from Suollagavallda profile show up to 35 % of coprophilous fungal spore Sporormiella along with a decline in the percentages of Betula and Salix pollen, and an increase in Juniperus which are good palynological indicators of grazing in the area. The pattern is very similar to some earlier observations from other reindeer herding sites in Sweden. The high percentage of coprophilous fungal spores in the so far analyzed samples suggests that the method can be used to date the timing and duration of reindeer milking in the Suollagavallda valley.