Re‐defining the natural range of Scots Pine (Pinus sylvestrisL.): a newly discovered microrefugium in western Ireland

Abstract

Aim Native Pinus sylvestris became extirpated in Ireland, during a massive population decline experienced throughout Europe. It was extensively replanted in Ireland during the 18th century from Scottish stock. We test the hypothesis that P. sylvestris in Rockforest Co. Clare did not become extirpated during the P. sylvestris decline, and persisted to present day independent of 18th century plantations. Location Rockforest, Co. Clare in Ireland. Methods Fossil pollen was counted from a terrestrial core. Radiocarbon dates and age‐depth modelling was used to ascertain the core chronology. Loss‐on‐ignition was carried out to investigate sediment accumulation history. Pollen was also counted from moss polster pollen traps to explore the deposition of P. sylvestris pollen in the surrounding landscape. Historical maps were consulted to investigate the longevity of other nearby P. sylvestris populations. Results A continuous record of P. sylvestris is reported. The core extends through the last two millennia, and reports a clear decline of P. sylvestris at c. 1550 cal bp. The P. sylvestris pollen curve recovers quickly after the decline event and persists at high levels up until the present day. The loss‐on‐ignition data reveal a stable accumulation of sediment with no major erosion events. The moss polster pollen traps show the core site is a suitable location for collecting pollen from the Rockforest P. sylvestris population. Historical maps demonstrate that none of the other nearby P. sylvestris populations extends further back than plantations in the early 18th century. Main conclusions The population of P. sylvestris in Rockforest Co. Clare survived the regional P. sylvestris decline, recovered and persisted right up to the present day, independent of introduction by human agency. Hence, we identify this microrefugium population of native Irish stock outside of the current understanding of the native range for this tree species.

Palaeoecological Evidence for Survival of Scots Pine through the Late Holocene in Western Ireland: Implications for Ecological Management

“…These findings are also supported by those of McGeever and Mitchell's [64] analysis of a radiocarbon-dated terrestrial core from Aughrim Swamp, which is located 650 m north-east of the Rockforest Lough coring site (Figure 1). Pollen preservation was good throughout the pollen profile, which extends from the present to 1600 cal BP/AD 350.…”

“…However, analyses of fossil stomata provided unambiguous evidence of local presence of P. sylvestris when Pinus pollen frequencies were as low as 2.8% [62] and 0.4% [63]. From a study of modern pollen deposition in the Rockforest area, McGeever and Mitchell [64] concluded that a Pinus pollen value of 5% indicated local presence of P. sylvestris in this area. The Pinus curve from Rockforest Lough is consistently high, never less than 38.2%, and greatly exceeds the critical pollen percentages.…”

Aran Islands, Western Ireland: Farming History and Environmental Change, Reconstructed from Field Surveys, Historical Sources, and Pollen Analyses

“…As regards the Gortlecka profile from near Rockforest, there are considerable uncertainties associated with the dating that are not alluded to, though these uncertainties were referred to in the initial publication (Watts 1984). Interestingly, a short unpublished pollen diagram by Coleman (1978) from Gortboyheen Lough in the northern central Burren (SM-F2; see pollen assemblage zones 2-4) has similarities to that published by McGeever and Mitchell (2016). Local survival of Scots pine at Gortboyheen is not, however, regarded as likely for various reasons including that there are no known records for the local presence of pine.…”

“…The two short pollen profiles that have been published suggest rather different local histories of pine. Furthermore, the published 14 C dates from Killarney and the Burren, that have been drawn on by McGeever and Mitchell (2016) to support their arguments, are inappropriate. The 14 C date cited from the northern Burren (Lios Láirthín Mór), for instance, relates to a profile that does not include the final pine decline (Jeličić and O'Connell 1992).…”

Scots pine (Pinus sylvestris) dynamics in the Welsh Marches during the mid to late-Holocene

“…While this demise was sudden in places, an increasing body of research has demonstrated that the timing and nature of this event are far from uniform (Blackford et al, 1992; Edwards et al, 1996; Edvardsson et al, 2016; Hall et al, 1994, 1996; Lageard et al, 1999, Payne et al, 2013). The decline has been attributed to various factors including climatic deterioration, increased competition with other tree species, anthropogenic effects, pathogens and volcanic activity (Bennett, 1984, 1995; Blackford et al, 1992; Hall et al, 1996; Manning et al, 2010; McGeever and Mitchell, 2016).…”