The distinctive pollen of the genus Acer has been recorded from all the sub-stages of the Hoxnian interglacial (Oxygen isotope stage 7 or 9) and from the first three stages of the Ipswichian interglacial (oxygen isotope stage 5), although in all cases identification to species level is not attempted (Godwin 1975). Most of the Hoxnian examples resemble Acer campestre (West 1980). Most of these interglacial records are low percentages of only 1 to 2% of tree pollen, although as Acer is a low pollen producer it may be that these records represent substantial Acer populations. Some Ipswichian records are of higher percentages, however, up to 10% of tree pollen and in one case over 20%, and Acer must have been a major component of the woodland at these sites. These high percentages may reflect local abundance of Acer, however, rather than its wider importance in the forest (Godwin 1975) and Acer macrofossils occur with the high pollen percentages. Acer campestre macrofossils have been recovered from the Cromer Forest Bed in Suffolk and show the presence of the species in Britain from the mid-Pleistocene at least. In the Holocene there are few records before c.5,000BP when Neolithic farming began to open the forest and create regeneration habitats for secondary woodland and scrub. Occurrences increase in late prehistoric times and after, probably because of woodland clearance favouring its growth. Acer is commonly recognised on later Holocene pollen diagrams from southern Britain. Pollen percentages are always low, however, even in areas of particularly favourable soils such as the chalk of southern England (Waller & Hamilton 2000), where consistent but low pollen percentages do not reflect the long-term importance of Acer in the woodland community (Rodwell 1991). In all cases pollen records are identifiable as Acer campestre until early modern times when A. pseudoplatanus was introduced. Pollen records are too few and low frequency to trace the spread of Acer campestre in Britain as is possible with more abundant trees which are high pollen producers. Almost all of the Holocene macroscopic records (fruits, wood and charcoal) have been found in an archaeological context. These occur in Wales and central to southern England and conform with the modern distribution (Godwin, 1975).