The deterioration of the site seems to have accelerated since the 1960's. Birch came to dominate
the once open areas. Wavy Hair-grass declined in favour of Purple Moor-grass and Heather
retreated into a few corners. The loss of plants included the extinction of Bell Heather (Erica
cinerea) as a Forest plant.
This deterioration may have been the result of a number of factors including drought and its
associated fires, lack of grazing and increased nitrification from acid rain. The second of these
(lack of grazing) may actually have been the least important as this is a wet heath/mire site
which in the past probably received relatively little management attention and should require
less maintenance than drier heaths (Gimingham 1992). Evidence for low levels of management
comes from the commoners who have remarked that they used to ensure their cattle passed
through the area as quickly as possible because of the nutrient poor vegetation (pers. comm.).
Nitrification by rain could be a significant factor so close to London and there is some evidence
of this as a problem on Dutch heaths and grasslands (Heil & Diemont 1983; Bobbink 1991).
However, once the successional process had begun it would create its own momentum as Birch,
as well as drying out a site, can significantly, and adversely for heath vegetation, alter the
nutrient status of the soil beneath it (Mitchell et al. 1997). Heather, and other specialist
heathland vegetation, would then struggle to reassert itself because the gaps and nutrient-poor
soil for the pioneering species would be lost.
Recent management
In 1989 a hectare of Birch dividing the remaining open areas was felled with stumps being
pulled out in some cases. Following this clearance, some trial soil-stripping was carried out in
three 25 x 25 metre plots, in December 1991, April and August 1992 respectively. The turf,
consisting of Purple Moor-grass tussocks, was removed and with it 2 to 5 cms of the organic soil
Essex Naturalist (New Series) 16 (1999)