NEWFERRY AND THE BOREAL-ATLANTIC TRANSITION

Area of Science:

• Palaeobotany
• Quaternary Science
• British Archaeology

Background:

• The expansion of alder (Alnus glutinosa) in Britain during the early Holocene (approx. 8000-5000 years ago) is a significant ecological event.
• Previous hypotheses often emphasized climatic changes, specifically increased wetness, as the primary driver for alder's establishment and spread.

Purpose of the Study:

• To investigate the factors influencing the establishment and expansion of alder in Britain between approximately 8000 and 5000 years ago.
• To evaluate the roles of climate change, sea-level fluctuations, and human activities in this ecological transition.

Main Methods:

• Detailed pollen analyses were conducted on Mesolithic layers from the Newferry site in Co. Antrim.
• Comparative analysis of evidence from multiple archaeological and palaeoecological sites across Britain.

Main Results:

• Pollen data indicate widespread disturbance of forest cover during the Mesolithic period.
• This disturbance, by locally reducing competition, appears to have been a key factor in alder establishment.
• Estuarine habitats played a significant role in the geographical spread of alder.

Conclusions:

• Human-induced forest disturbance was a critical factor, alongside habitat availability, in the establishment and expansion of alder.
• While permissive, the onset of a wetter climate was likely not the primary driver, contrary to previous assumptions.
• The findings highlight the complex interplay between environmental changes and anthropogenic influences on prehistoric vegetation dynamics.