Vascular plant and bryophyte survey from a 33-year chronosequence on bare chalk, Dorset, 2019-2020

A total of 13 transects (16 m in length) were set up in July 2019, with one in each of the excavated blocks dated 1986, 2004–2008, and 2013–2018 (2 blocks were excavated in 2016). The percentage cover of vascular plant species were recorded in 50 cm x 50 cm quadrats every 1 m along each of the 13 transects, giving a total of 208 quadrats. Vascular plants were identified to species level, with the exception of Taraxacum microspecies. The percentage cover of bryophytes were recorded in February 2020 using the same methodology, but with a 20 cm x 20 cm quadrat. Two plots were not recorded for bryophytes, the first of which (excavated in 2006) was due to rubble left on the plot, which would have influenced the colonisation of bryophytes and the second plot (excavated in 2016) was excluded due to time constraints, as there was already another plot recorded of this age. Bryophytes were identified to species level, with the exception of a few small and/or infertile individuals, where it was only possible to classify specimens to a group level (affecting some Didymodon and Bryum species).

Data were collected by experienced field ecologists. Paper data sheets were digitised into Excel and were checked for any anomalies.