The Lodge Road bog is a pool of tranquillity at the centre of the commuter-traffic hum. Both my mobile phone and walkie-talkie radio signals have died, and only a few darting dragonflies break the stillness. Sponging up the sunlight, the bog glistens, a curve of brilliant green amid the deep summer gloom cast by surrounding beeches.
On the outer orbit of London, the survival of this fragile place, the most important habitat of its kind in Essex, seems astounding. Carbon-dating reveals that the first layer of vegetation was laid down here more than 4,000 years ago. Ponded back by a Neolithic trackway, or just some natural lip of gravel, the area was deepened by road building for the various incarnations of nearby Copped Hall since the middle ages.
I reach the northern bank through a wall of six-foot-high bracken and follow deer tracks out onto the drier upper bog. Here the grazing fallow deer have flattened soft rush into a thick thatch, providing a stationary raft on which I can safely stand to view the floating vegetation. At its heart, the bog is dominated by a deep carpet of sphagnum mosses flecked with cotton grass. Of the five sphagnum species here, all exceptionally rare in southern Britain, I can see the two main ones, Sphagnum palustre around the outer edges and S. fallax in its wetter centre. But it’s the constellations of jade stars of another moss, Polytrichum commune (common hair-cap), that draw my gaze.
I can’t venture across these treacherous mossy layers for fear of the watery void beneath, so I use binoculars to explore the surface, decorated with hundreds of carnivorous round-leaved sundews (Drosera rotundifolia) with their sticky, glinting leaves busily glueing insects. Encircling this carnage, a ribbon of sharp-flowered rush provides refuge for minute ebony Neoascia hoverflies, which weave delicately through its elegant panicles of nut-brown florets.
Patches of open water, patterned with leafy coins of marsh pennywort, mark the bog’s edges, where a “living fossil” from the Palaeozoic, water horsetail, stiffly guards the boundary between woodland and wetland. Crossing here is to step back in time.
