A palaeoecology of upland transhumance sites: a long view on the timing, economy and environmental impact of seasonal settlement sites in the Mourne Mountains, Northern Ireland

Context
Archaeological and historical evidence attest that transhumance was commonplace across Ireland during the last millennium. This largely involved the movement of people and their cows to upland pastures for the summer months to create space in the lowlands for arable farming. Significant gaps in understanding remain relating to the timing of and motivations for seasonal settlement, the activities that herders engaged in and the impact of land-use on the local environment.

Objectives
Here, we use a palaeoecological approach to produce records of past land-use and settlement history that will resolve extant questions regarding the timing of transhumance, the activities of settlers and their impacts on the landscape.

Methods
We collected blanket peat sequences from the immediate vicinity of two transhumant sites in the Mourne Mountains, County Down, Northern Ireland. We analysed sequences for pollen and non-pollen palynomorphs to understand the landscape history of both sites. Cryptotephra analysis was employed to robustly date these palaeoenvironmental records.

Results
We date the commencement of land-use activity at occupation sites studied in the Mournes to the mid- to late twelfth century CE, and show that people grazed livestock and grew cereals in these localities. These findings question the long-held view that occupation reflects summer herding, and highlight that transhumance may have emerged from a longer tradition of permanent upland settlement. We also find that the impact of these activities was largely local, with no discernible impact on the surrounding heath-dominated landscape. Results place the demise of activity during the early nineteenth century CE, probably due to change in favoured stock type from cattle to sheep.

Conclusions
Results shed new light on upland settlement in Ireland during the last millennium, showing that settlers took part in a more diverse array of farming activities than was previously believed. In addition, our results challenge current interpretations of the history of transhumance practices in Ireland finding that its origins may stem from the demise of permanent upland settlement, and demonstrate the resilience of past populations in what are today regarded as ‘marginal’ environments.