EVENTS AT AND AROUND THE FIRST AND SECOND ULMUS DECLINES: PALAEOECOLOGICAL INVESTIGATIONS IN CO. TYRONE, NORTHERN IRELAND

Abstract

SUMMARYPercentage and concentration pollen diagrams from tbe sediments of two adjacent inter-drumlin bollow lakes near Dungannon, and in two cores frot-n Lougb Catherine, suggest tbat only small reductions in tbe pollen frequencies of trees sucb as pine and, at some sites, birch and oak, accompanied reduced Ulmus at the elm decline in tbese parts of Co. Tyrone. Tbey also confirm tbat Pteridium aquilinum could sporulate and many berbs were able to flower more freely owing to an opening of tbe tree canopy. Seventeen radiocarbon dates provide cbronologies for tbe sites and date tbe elm decline to between 5050 and 5375 B.P., the subsequent start of increased elm pollen percentages to between 5010 and 4850 B.P., and tbe beginning of a second decline in elm pollen to hetween 4330 and 4260 B.P. Tbe initial decline in elm pollen values may have been caused by disease and tbis reduction was superimposed upon a background of small-scale clearances wbicb continued after a general elm regeneration. Tbe question of a general similarity and causation of tbe second elm decline in Ireland and elsewhere is considered. Chemical, magnetic and pollen preservation data from tbe Co. Tyrone sites suggest episodes of erosion occurring at tbe first elm decline and otbers at tbe second elm decline.

Dating the introduction of cereal cultivation to the British Isles: early palaeoecological evidence from the Isle of Man

“…These sites are shown on Fig. 1b and Table 2, which also include slightly younger, between 5600 yr BP and 5800 yr BP, pre-Ulmus decline cereal pollen dates from the British Isles (Pilcher and Smith, 1979;Hulme and Shirriffs, 1985;Hirons and Edwards, 1986;Edwards and McIntosh, 1988;Smith et al, 1989;Mighall and Chambers, 1995), but not several examples closer to the Ulmus decline itself (Edwards, 1988(Edwards, , 1989. For example, cereal pollen that occurs within a well defined clearance phase dated ca.…”

“…The establishment of the full Neolithic may well have been much more of a punctuated or piecemeal process, but it is very difficult to observe in most areas because of incomplete archaeological and low resolution palaeoecological data (Edwards and MacDonald, 1991;Edwards et al, 1996). By the time of the much-discussed Ulmus decline (Groenman-van Waateringe, 1983;Hirons and Edwards, 1986;Parker et al, 2002) about 5000 14 C yr BP (all BP ages in this paper are in uncalibrated radiocarbon years), however, fully Neolithic farmers were well established in northwest Europe in all but the most marginal environments (Price, 2000;Woodman, 2000). Where rapid displacement did not occur, the transition took place as a complex and protracted phase of cultural substitution, with the gradual introduction of new techniques as part of a process of acculturation.…”

Flandrian vegetational history of southeastern England. Pollen data from Pannel Bridge, East Sussex

“…Confirmation that this is the 'elm decline', found in most north-west European pollen diagams in the mid-Flandrian {c. 5000 BP), is provided by the date of 5040 ±80 BP (SRR-2888). This event has been ascribed to climatic change, various forms of human activity and disease, with several authors favouring a combination of human activity and disease (Huntley & Birks, 1983;Groenman-van Waateringe, 1983;Birks, 1986;Hirons & Edwards, 1986).…”

Late‐ and post‐glacial vegetational change at Black Loch, Fife, eastern Scotland – a multiple core approach

“…The elm decline, usually considered to coincide with the first major human impact on the vegetation cover of north-west Europe, is shown to be a recurrent rather than a unique feature and, while not of such a complex nature as that encountered at WaunFignen-Felen in South Wales (Smith & Cloutman, 1988), extends still further the phenomenon observed in Ireland (Hirons & Edwards, 1986). Since that event, the Black Loch area has experienced a conversion from a dense mixed deciduous forest to an open landscape with virtually no woodland cover ex'cepf that provided by planting on estates.…”

“…Such reasoning applied to e\ ents surrounding the first elm decline and subsequent recovery in woodland could also apply to the recurrent cycles of change seen in BLII and to a lesser extent in BLIV. Multiple elm declines and related vegetational changes have been noted elsewhere somewhat rarely (though see Hirons & Edwards, 1986;Smith & Cloutman, 1988) and suggest that the uniqueness of the classic elm decline is perhaps over-emphasized. Also, it seems entirely possible that such declines occurred prior to the commonly-reported date of c. 5100 BP, but that earlier reductions in Ulmus might remain undetectable wherever elm trees formed a small proportion of pollen-producing taxa.…”