Climatic significance of the marginalization of Scots pine (Pinus sylvestris L.)c. 2500 BC at White Moss,south Cheshire,UK

Abstract

Subfossil wood from White Moss, south Cheshire, has become the focus of palaeoenvironmental research employing not only conventional coring, pollen analysis, radiocarbon dating and dendrochronology on pine and oak, but also the exhumation ofin situ peat areas and dendroecology of the pine ring-width records. Initial dendrochronological research at the site yielded five pine chronologies dating from 3520 to 2462 cal. bc. These and other data indicate three episodes of pine colonization of the mire in the period between 3643 and 1740 cal. bc. Comparison of the pollen and spore records suggest that pine became marginalized at the sitec. 2500 cal. bc after successive episodes of increased wetness, and this may represent a staged response to climatic deterioration. Two oak chronologies were dated by reference to the Belfast and to English oak master chronologies to 3228–2898 bc and 2190–1891 bc, respectively, showing the possible co-existence of pine and oak on the mire for part of the time. Further dendrochronological work on subfossil pine at the site resulted in a chronology (WM4) that was cross-matched with pine from elsewhere in England, and subsequently dated absolutely to 2881–2559 bc. Detailed dendroecological information, such as fire episodes and periods of environmental stress indicated in the tree-ring records, have been assigned, precisely and accurately, to calendar years in prehistory. The detailed data show the potential for both dendroecological and wider palaeocli matic and palaeoenvironmental information that may become available from prehistoric bog-pine chronologies, which might then permit precise correlation and comparisons of proxy-climate data between sites.