Guided tour of Dawcombe nature reserve

On Sunday, June 26^th some 24 Members enjoyed a fascinating and informative walk around The Dawcombe nature reserve, led by the Site Warden, Simon Humphreys.

This site was previously owed by Smith Kline Beecham, then Pfizer who, in 2000, sold it to the Surrey Wildlife Trust for a nominal £1. Access to this site is currently restricted so we were fortunately to have been given such full access.

The reserve occupies some 70 acres of nutrient-deficient chalk scarp-land surrounding a comparatively nutrient-rich dry river valley mainly filled with Hawthorn scrub while above the grassland, on top of the hill, is a wood with Beech, Ash, Field Maple, White beam, Hazel and Spindle plus some ancient Yews and a clump of conifers.

The chalk grassland is maintained by volunteers who carry out development and scrub management projects aided by some controlled grazing by a herd of Belted Galloway cows loaned by Surrey Wildlife Trust.

In part because of its variety of habitats, the reserve boasts a rich variety of typical chalk-land plant species such as the tall greenish-yellow spikes of Wild Mignonette and of the Common and Dark Mulleins, Hairy St John’s Wort, Nettle-leaved Bellflower, Viper’s Bugloss, Eyebright and many, many more including some 13 species of orchid.

Hairy St John’s Wort (Hypericum hirsutum)

Simon not only named the plants and insects that we found but also gave some interesting background information such as the partially insectivorous nutrition of the Teasel, the simulation by the Bee Orchid (Ophrys apifera) to attract the Solitary Bee (Eucera) and the synthetic female pheromones produced by the Fly Orchid (Ophrys Insectifera) to lure a male fly to attempt to mate with it and so achieve pollination. In addition Simon explained that the orchids produce very small seed with little endosperm and so, following germination, rely for their nutrition on a mycorrhizal fungus, the growth of which is inhibited by high nitrogen content in the soil. They therefore flourish on poor soils and can take some 2 – 3 years to produce their first leaves.

Pyramidal Orchid (Orchis pyramidalis)

Bee Orchid by Jean Nobbs

As well as environmental management to encourage the growth of chalk-land species the reserve also contains some areas of the grassland that had been fenced to deter grazing by rabbits and so encourage the growth of sensitive species such as the plant parasite, Dodder, and also the orchids which have their flower heads removed but not eaten by rabbits, presumably because they look and smell like food but taste disgusting.

In addition to the plant species present the reserve also boasts some 56 species of bird, plus Roman snails, and a variety of insects including 36 species of butterflies such as the Brimstone, Comma, .Marbled White and Meadow Brown.

Over all a very enjoyable and instructive morning.