Remarkable botanical records from Corrour in Westerness (v.c.97), including Baldellia repens (Alismataceae) and Illecebrum verticillatum (Caryophyllaceae), new to Scotland

Abstract

Biological recording in Britain has increased in accessibility and popularity due to recent technological advances. However, remote locations may still be under-recorded, particularly for aquatic plants and taxonomically challenging groups. We describe a set of notable botanical discoveries made in 2021 at Corrour in the Scottish Highlands (v.c.97 Westerness), including Baldellia repens, Illecebrum verticillatum (new to Scotland) and six British altitudinal records. At the time of writing, there are now four Nationally Rare vascular plant taxa recorded on the estate and 29 Nationally Scarce taxa. These findings demonstrate the value of collaboration between land managers, ecologists, BSBI staff and the local community. Both B. repens and I. verticillatum are well established at Corrour in considerable abundance and with clear evidence of regeneration. B. repens also occurs in the Tay catchment and may have arrived at Corrour via vegetative dispersal by waterfowl. The origin of I. verticillatum is more ambiguous but suggested mechanisms of dispersal include forestry, the railway or hydroelectricity workings. Despite a likely element of accidental human-mediated spread, I. verticillatum should be considered an intriguing addition to the flora of Westerness. Climate change could facilitate further establishment of this taxa in northern parts of Britain, and it is likely that other new records of both B. repens and I. verticillatum await.

High mountain trees: altitudinal records recently broken for eleven different tree species in Britain

“…In fact, some records were broken several times in quick succession. Betula pubescens was recorded sequentially by the author on Corrour Estate at 924 m (Watts et al, 2022b), 928 m and 949 m on Stob Coire Sgriodain, and then at 968m on Beinn Eibhinn, before the current record of 1026 m was achieved on nearby Ben Nevis (v.c.97). In 2022, P. sitchensis was found at 1030 m on Schiehallion (v.c.88) and Beinn a'Chaorainn (v.c.97), and at 1120 m on Ben Macdui (v.c.92), before being discovered at 1125 m on Braeriach (v.c.92).…”

“…For example, P. sylvestris, S. aucuparia and B. pubescens are emerging above vegetation height at high altitudes on Mar Lodge in the Cairngorms due to a reduction of deer densities on a landscape scale (Rao, 2020). With other Highland estates also lessening pressures from overgrazing (Watts et al, 2022b), further expansion of treeline habitats is anticipated where there are suitable conditions for tree growth and a viable seed source. It is therefore important to account for historical land use legacies, management practices and their interaction with climate change when considering upslope colonisation by trees in the future.…”

“…Mapping relict populations and incidents of regeneration is useful for locating propagation sources for restoration projects and examining the range of environmental conditions suitable for tree establishment (Montane Scrub Action Group, 2016). The full extent of existing and potential habitat may still be underrepresented across the Scottish Highlands, because new records of montane trees and sub-arctic willows continue to be made, particularly at sites where grazing pressures are reduced (Wilson, 2015;Watts et al, 2022b;Botanical Society of Britain & Ireland, 2023).…”