Therapia Lane Rough is now a fraction of its former size and glory. In the early 1990’s, this site was one of the most botanically diverse in Greater London, boasting at least 230 different species of vascular plants, a huge number for London.
The site was a 10ha area of former rail sidings and post-industrial wasteland, the majority of which was then developed on. It appears that prior to industrialisation (Ordnance Survey map 1868) there was a large field here, occupying the same boundaries to the east and west but extending further north. It appears that the Surrey Iron Railway, which opened in 1855, ran along the line of the current Tramlink line.
Over the last decade or so, Therapia Lane Rough has not received any management and this, along with the destruction of the majority of the site, has influenced the remaining habitats and species present. In 2008, we started to manage this site to try to restore some of its former glories.
Wildlife & Habitats
After no management for 10 years, the site is now dominated by thick bramble Rubus fruticosus agg. scrub, within this are dog rose (Rosa canina) and hawthorn (Crataegus monogyna).
In 1990, this site contained 27 native species considered as rare in London. In 2006, this was down to 3 species: round cranesbill (Geranium rotundifolium), restharrow (Ononis repens) and vervain (Verbana virgatum). The small areas of remaining grass are dominated by common species, such as perennial rye-grass (Lolium perrene) and false oat-grass (Arrhenatherum elatius), with sadly no trace of the more interesting and rare species that once flourished here.
Several common bird species (including migrant warblers such as lesser whitethroat (Sylvia curruca) and garden warbler (Sylvia borin)) were reported to breed on site, whilst 15 species of butterfly were recorded on one day. Of note for butterflies are small copper (Lycaena phlaeas) and brown argus (Aricia agestis).
Now that the SNCV has finally accessed the site, we shall be undertaking management to remove the eyesores and fly-tipping, which have been dumped on the site. We shall be undertaking detailed surveys of the extent of the scrub on site, so that when we thin the scrub to promote other plant life, we can measure exactly how effective our management is. Basic surveys for birds and insects will also be occurring over the course of the next few years. One of the biggest jobs will be the removal of some large stands of the invasive species Japanese knotweed (Fallopia japonica). This plant is extremely persistent and can cause damage to concrete and even house foundations. We will be undertaking a programme of cutting and burning the stems on site and then spraying the cut stems with a herbicide to try to control this plant, in line with DEFRA legislation.